The intent of this wiki entry is to recap all of the recommended resources and to place them in one spot. 

For those that are interested in migrating to SBS 2008 chances are that you have an existing SBS 2003 server.  There are very documented steps to migrate from SBS 2003 to SBS 2008.  Do not be intimidated by these resources.  Migration of any active directory network should be planned and thought out in advance. 

Migrating from SBS 2003 to standalone server parts.

If you plan to migrate from SBS 2003 to standalone server parts the process can be done in several ways.

1.  Use the SBS 2003 transition pack.  The Transition Pack is a Microsoft product you purchase which provides you with a combination of software and transition licenses that enable you to continue operating the same server installation after the software tool has updated the installation removing the restrictions of SBS 2003 product.  Restrictions to SBS include that the server must hold all the FSMO roles.  It must be an Primary Domain Controller.  It cannot be a trust with another domain and cannot have "child domains".  Once you install the transition pack these restrictions are removed. It's important to note that the Transition Pack can only be run on SBS 2003 R2 based installation, it requires compliance with service pack and preparation prerequisites which may include uninstalling, disabling or re-installing many third party applications.

2.  Add an additional server to the network as an additional domain controller.  You will then need to decommission the SBS server from all Active Directory integration, network service roles and application configuration to continue forward working with the new domain controller.  If you are unsure of the details of how to address this type of transition, the migration resources provided by Jeff Middleton at www.sbsmigration.com incorporate this basic concept into a fully detailed step-by-step project solution. 

Migrating from SBS 2003 to SBS 2008 or SBS 2011 standard

1.  Clean install.  For some folks that do not know the history of the active directory domain they are migrating from, or that they feel that the size of the users is such that a clean install makes sense for them, a clean install of SBS 2008 or SBS 2011 standard means that you will need to manually unjoin each workstation from the old server and rejoin it to the new server.  Before doing so, ensure that you export out to pst files the mailbox contents (using exmerge or export inside of Outlook).  Then once you have joined the workstations back to the new domain you can use file/inport to import back in the email into the Exchange. For this process to work, the mailboxes have to be below 2 gigs in size.

2.  Migration using Microsoft methodology.  The Microsoft migration method has been extensively documented and used by many people.  It involves a process of ensuring that the health of the old network is proper and then you fill out an xml file that will be accessed by the new server once it is installed.  Using the proper procedure the new server will initiate a "Join to Domain" installation in communication with the old server during the install process, installing and configuring the new server in "migration mode".  This installation approach preserves the domain in the manner of adding another domain controller and installing the entire SBS 2008 suite of applications including Exchange 2007 as part of an uninterrupted setup sequence. After setup is completed, you will then need transition all operations from the existing production server to the new SBS 2008. This approach concludes when you decommission the original SBS server from all Active Directory integration, network service roles and application configuration to continue forward working with the SBS server. 

For SBS 2011 the process is similar with the changes in the documentation reflected to due the underlying change of the Exchange 2010.

Resources for this process include Microsoft official resources as well as third party blog sites that have migrated using this method.

• www.sbsmigrationtips.com is a redirect to an official SBS blog site that is a checklists of things to check before you begin migration.
• Read the SBS migration guide - http://go.microsoft.com/fwlink/?LinkId=122143.
• Download the SBS Migration checklist.
• Review the third party guidance at Philip Elder's blog.
• Review all of the Migration related blog posts at Susan Bradley's blog.
• Consider using Virtualization as a tool to enhance your migration process.

3.  Additional third party migration resources.

There are two additional sources of documentation to assist you in your migration strategy. The two sources are complementary as one resource provides the guidance of planning for a migration, and the other resource provides a means to perform a SBS 2003 to SBS 2008 migration while providing a fall back process.

• SBSmigration.com is a unified source for migration projects offering step-by-step documentation, tools and support. The website and resources are provided by Jeff Middleton SBS-MVP who introduced the concept of Swing Migration as a standardized migration project approach for SBS and non-SBS platforms. Swing Migration takes the concept of introducing an additional intermediate domain controller to the domain as just the initial step to then moving the entire project offline without modifying or interrupting the existing operations. This ensures that you keep the original server intact for the duration of the migration process ensuring that you have "nothing to undo" while in construction, or as a fallback if you choose to abort the new server deployment. The new server you construct offline can be built with the same domain, same server name and IP, and as a transparent replacement for the original server.
• Zero Downtime Migration- a book by Karl Palachuk is a series of checklists and planning tools to assist you in planning for a migration in which a new domain is built from scratch with clean installations and preparations of all the workstations. 
• Small Business Server 2008 - Installation, Migration and Configuration  - a book by David Overton that provides a step by step with screen shots of the Microsoft Migration method.  While this pertains to 2008, the documentation and scripts for copying data is very helpful in moving over the data folders.