What is the best way to go about upgrading TFS 2005 to 2008? Also, what about the Team Build scripts ("Build Types"), are those compatible with Team Build 2008 or do they need converted/migrated somehow?
First and foremost - backup everything! The databases, the machine itself... You can never be too careful.
I was able to upgrade the TFS installation at my company by using these resources:
http://olausson.net/blog/CommentView,guid,6f97b619-a5ac-41af-a908-f099d49a3b16.aspx http://blogs.msdn.com/sudhir/archive/2007/05/31/upgrade-2005-with-wss2-0-to-orcas-wss3-0.aspx http://weblogs.asp.net/dmckinstry/archive/2007/08/27/considerations-on-using-tfs-2008-with-visual-studio-2005.aspx
It's not that hard and can in fact be done in a couple of hours, with better luck.