And here is some more guidance around SBS migration, posted by Nick King, Senior Technical Product Manager for SBS at Microsoft:
Recently I received the feedback that we needed a better way of representing all of the tasks during the SBS 2008 migration process. We spent some time looking at what could be done to support a smoother migration, and came up with this document for partners and IT Pro’s.
While you’re migrating you should also check out these great resources;
Practice you migration with this click through demo
Or check out Jeff Middletons third party swing migration