Back to the history of VCS, anyone still remember and used SCCS? Well, I did use it...

Interesting statistics, this show how important it is to have well structured and focused change sets as much as possible.

A good reference on most of the branching patterns you can find. From this you can derive your project wide policy. Also it's spot on when it says that branching is easy but each time you branch you need to keep in mind how you're going to merge.