It's finally here! Our first real guidance on branching & merging has been posted, on a Codeplex wiki no less. I reviewed several drafts of the paper, but the real credit goes to Mario for driving our (the product group's) side of the process. Congrats to him, the UE team, and the VSTS Rangers on this milestone.
Definitely watch the recent Channel9 "Branching 101" interview while you're at it. I get asked for branch/merge guidance constantly on the MSDN forums; while there are lots of good resources on the web, the interview & whitepaper above make relevant recommendations much easier, especially for TFS users. If you finish those two and still want more, make CMCrossroad's encyclopedic Streamed Lines your next -- and probably final -- stop.
Next in the pipeline: best practices for Team Projects, headed up by the same Doug Neumann of Channel9 fame. (he doesn't have a blog, so I'm going to embarrass him by linking up his old homepage instead) What substructures can I create within a Team Project? What do the TFS Team Project limits mean for my org? Where do I put shared code? If you finished the branching docs but still had questions like these, that was intentional -- branches and team projects are orthogonal, far moreso than many people think. Stay tuned.