I'm enjoying the latest installment of Source Control HOWTO.
Best Practice: Don't create a branch unless you are willing to take care of it.
A branch is like a puppy.
We adopted subversion for new projects several months ago and are very happy with it. Now we are about to release the first version of one of those projects, so it should be fun to see how branch/merge works out. I am always nervous about this, having experienced disasters using both SourceSafe and CVS, so let's hope for a pain free experience this time.