What to govern in SharePoint
As you design your SharePoint services, governance is critical:

• Quota templates The size limit (amount of data) placed on each site collection should be determined by the service level for a particular site collection. In addition you can specify the maximum size of files that can be uploaded. To establish the site collection's service level it should be ranked in expected usage and criticallity among other site that will compete for resources in the farm.
  The value also indicates the limit that triggers an e-mail alert to the site collection administrator.
• Self-service provisioning
  Users can be allowed to create sites on a self-service basis. As a best-practice, using a custom form and workflow to provision sites will allow you to enforce governance rules like size and access levels, while providing a self-service interface.
• Customization policy
  The amount of customization allowed at each site level must be carefully considered. Keep in mind that some types of customization are global to the farm. As an example, services that allow self-service site creation may include hundreds of sites that share a single Web application. In which case, you could limit customizations to only those in the user interface, such as adding Web parts to pages. In a service that provides virtual or physical isolation of the server farm, such as for an enterprise portal site, you might allow a large range of customizations, such as custom workflows and event handlers.
• Asset classification
  Information should be classified according to business value, simply high, medium, or low will do. Also consider whether the information is public or internal only. This can help establish publishing rules, size limits, content expiration and many other attributes of managing your content and configuration.
• Lifecycle management
  You should plan for both long-term and short-term site lifecycles. Some sites are expected to last for only a short period of time, such as, a project specific site or a site pertaining to a business acquisition. Guidelines should be created around site lifecycles, content archival, and site management for each lifecycle established. Records management and data retention should also be considered.
• Branding and templates
  Site templates are simply a site definition with saved customizations. Site templates can be used at the site collection level or globally across your farm to enforce consistent branding.
• Data protection
  A testable backup and recovery plan should be in place before you begin any SharePoint project. Establish service levels for each category of site based on criticality. An SLA should establish recovery time, criticality of data, outage windows, etc.
• Training
  One of the most frequently over looked tasks is training your end users. This is probably the most important. Make sure that the training addresses each role and access level. A good training plan is the key to product adoption and ultimately the projects success.

If you are planning a Lotus Migration:
Here are a few options:
  Free but very robust, Transporter Suite for Lotus Domino Resources for Moving to the Microsoft Collaboration Platform
Other Tool suites:

• http://www.optimusbt.com/
• http://www.casahl.com/home/home.html
• http://www.quest.com/notes-migrator-for-sharepoint/
• http://www.unify.com/Solutions/ComposerNotes.aspx
• http://www.protogroup.net/
• http://www.binarytree.com/website/msg/home.nsf/vContentW/0F21EE8C69174846862572C1006A6072
• http://interoptips.com/

If you are Planning Integration:
If you have a Lotus Notes environment and you have MOSS, you're probably thinking about integration. Often in this type of environment you want to keep Lotus as your messaging platform and host custom Lotus application, but SharePoint is used for document management and content collaboration.

From my research the most comprehensive integration solution that I have found is, Mainsoft SharePoint Integrator for Lotus Notes. Take a look at the product overview here: http://dev.mainsoft.com/Default.aspx?tabid=315.

Here are some of the Mainsoft SharePoint Integrator for Lotus Notes features from their site:

• How do you navigate SharePoint sites from Notes?
  Use the list pane to navigate sites, sub-sites, document libraries, and folders using the back/forward buttons, favorites, and breadcrumbs. You can also search for documents.
• How does the Search function work?
  From the Notes sidebar, select the Search button in the SharePoint document toolbox to search either an entire SharePoint site or a specific document library, depending on the current navigation state. The results will be displayed within the sidebar panel, along with the context surrounding the search term or terms.
• Do you integrate with IBM Lotus Sametime?
  Yes. Notes 8 users that have the Sametime plug-in installed and are logged into a Sametime community can see SharePoint document authors, last modifiers, and check-out holders using Sametime presence status. They can also initiate a Sametime IM session with these contacts and drag-and-drop document links to the Sametime IM chat window.
  Our professional services team offers a solution that packages the SharePoint Integrator configurations as a plug-in to the Sametime client. If you are interested in this solution, check our Solutions page or contact a Mainsoft representative.
• What are your options for attaching SharePoint documents to Notes applications?
  Users can drag-and-drop one or multiple documents from the Notes sidebar to a Notes e-mail, calendars entry, task, team room, or any Notes application that supports attachments. The drag-and-drop feature attaches a copy of the SharePoint document, while dragging-and-dropping using the Alt key inserts a link to the SharePoint document.
• What are the options for uploading documents to SharePoint using the Notes sidebar?
  You can drag-and-drop attachments either from a Notes application, such as an e-mail, or from your file system to the Notes sidebar. If a document already exists in the library, a new version will be created according the versioning setting defined in the SharePoint library.
  The SharePoint Integrator also provides a SharePoint button for the Notes mail application for uploading attachments to a SharePoint location specified by the user. To save e-mail storage space, and encourage using the collaboration site, users can opt to replace outgoing documents with a link to the stored document.
  Users can also create a new document directly from the Notes sidebar using a template defined in SharePoint.
• How does SharePoint Integrator handle multiple content types?
  SharePoint Integrator prompts users to select the SharePoint content type when they upload a document into a document library that contains more than one content type. SharePoint customers use content types to build SharePoint workflows, retention policies, and routing to the records center.
  On the other hand, if you don't want to prompt users to select the content type, clear the check box Select content type during document upload in SharePoint preferences, and the default content type will be used instead.
• How does SharePoint Integrator handle required fields when a new document is uploaded?
  SharePoint Integrator detects when a document has required fields that need to be edited by the user, and it automatically opens the property sheet window as the document is uploaded. All fields defined for this document are displayed, and required fields, which need to be edited before the document can be checked in, are highlighted.
• Can you access SharePoint metadata fields from the Notes sidebar?
  Yes, SharePoint Integrator enables you to view and update SharePoint document metadata. Select Properties from the document context menu to open the property sheet window and use the input forms provided for all SharePoint types.
• Can you view a custom SharePoint metadata field as a column in the Notes sidebar?
  Yes, you can add SharePoint custom fields to your visible columns in the Notes sidebar. Through the Notes preferences, you can open the Visible Columns dialog and enter any custom column name you want to add.
• Can I create custom views of SharePoint lists in the Notes sidebar?
  Not yet. The current release allows you to modify your view by selecting the SharePoint columns that will be visible in the sidebar. You can also set the order of the visible columns and sort by any of them. A future release will also allow you to define multiple views, filters, and style information.
• Can you check-out, check-in, and access a document's version history using the Notes sidebar?
  Yes. A common workflow is to check-out existing documents, open the documents directly on the SharePoint server, and check documents in from the Notes sidebar. You can also use the version history dialog to revert to and delete older versions of the document.
  Mainsoft SharePoint Integrator works according to the versioning setting defined in the SharePoint library, prompting users to select a minor or a major version.
• Can you open a SharePoint document using the Notes sidebar directly from the SharePoint server, without creating a local copy?
  Yes, when you open an Office document from the Notes sidebar, you get all the SharePoint server functionalities available in Office desktop applications.
• Can you open additional documents, other than Microsoft Office documents, from the SharePoint Integrator sidebar application?
  Yes, you can open all your documents from all types using Mainsoft SharePoint Integrator. SharePoint Integrator relies on the file types defined in your Windows environment, and it will launch the application associated with the type of the selected file.
• Can you save Notes e-mails to SharePoint using SharePoint Integrator?
  Yes. Simply drag-and-drop e-mails from your Notes application to the SharePoint sidebar panel, and SharePoint Integrator will create a compound document in SharePoint that contains the full e-mail, including the headers (sender, subject, recipients, date, ...), body, and document attachments. Saving e-mails on SharePoint allows users to share e-mails with team members, without filling up everyone's inboxes and without team members having to search through thousands of e-mails stored in a Domino folder.
  In addition, compliance with government regulations and statutes requires publically-traded enterprises as well as companies in several industries to document business decisions. The context is often times detailed in e-mails that can now be saved on SharePoint sites.
• In what format are e-mails saved on SharePoint?
  E-mails are saved as .eml documents in SharePoint, a file format derived directly from the SMPT mail standard protocol. This protocol is supported natively by SharePoint and can be indexed and searched. When accessing the SharePoint Web interface through a browser, the .eml file is displayed with the full formatting fidelity preserved, including the e-mail headers, body, and attachments.
• How do you handle multiple e-mails with the same subject?
  The name of an .eml document, which is a Notes e-mail in SharePoint, is derived from the e-mail's Subject. When multiple e-mails with the same Subject are stored in the same SharePoint location, a trailing index is appended to the document name.
• Can you save e-mails alongside Office documents?
  Yes, you can save Notes e-mails into any SharePoint document library, including libraries that also contain Office documents. This feature allows teams to organize information based on business activities rather than on document formats.
• What are your options for retrieving e-mails from SharePoint?
  Notes users can view, edit, and forward e-mails stored on SharePoint in their native Notes format. Extranet users can view Notes e-mails from their browser, with the document attachments displayed as internal links. From Microsoft Internet Explorer, the e-mail is displayed within the browser window. When using other browsers, e-mails will open using the application associated with the .eml type, such as Outlook Express on Windows XP or Windows Mail on Windows Vista.
• How do e-mail headers relate to SharePoint metadata fields?
  SharePoint Integrator introduces the ability to define the mapping between mail headers (Sender, Subject, To, Cc, Date, ...) and the SharePoint metadata fields using Notes Preferences. If the SharePoint library has some of these fields defined, SharePoint Integrator will copy the corresponding mail headers to these fields.
  Once the e-mail fields have been mapped to the metadata fields, the SharePoint administrator can create custom SharePoint views for efficiently displaying e-mail messages through the Web interface.
• Can you save outgoing e-mails on SharePoint?
  Yes. To simplify the process, users can select the Save e-mail to SharePoint option on the SharePoint button when they compose an e-mail. As the e-mail is sent, it is saved in the default SharePoint location for e-mails or a location specified by the user.
• Once users begin accessing SharePoint from Notes, will they have any reason to access SharePoint through the Web user interface?
  We designed Mainsoft SharePoint Integrator to facilitate the most common workflows, such as attaching documents in e-mails or uploading documents received through e-mails. Operations used less frequently, such as creating new SharePoint sites or document libraries, or modifying library settings, are not exposed through Mainsoft SharePoint Integrator. Users will need to access them using the SharePoint Web user interface.
• Does Mainsoft offer a way to access Notes data from the SharePoint Web user interface?
  No, Mainsoft SharePoint Integrator works the other way around. If there's a significant demand for accessing Notes data from SharePoint, we may re-evaluate our offering.
• Do you support Domino Web Access?
  No, SharePoint Integrator integrates with the Notes rich client and does not currently offer a Domino Web Access integration.
• Do you support localized environments?
  Yes, you can run the SharePoint Integrator in a Windows-localized environment, with a Notes-localized installation and against SharePoint sites localized in any language. However, in version 1.5, the SharePoint Integrator menus and messages remain in English.