I saw Rob Caron mention this new MSDN article, and it's a topic that comes up relatively frequently. If you've wanted to know more about different strategies for organizing your branches, this article provides a nice overview and links for you to dig deeper. Another link that may interest you is an article on branching models mentioned in the post, Branching Models.
Branching and Merging Primer
Developer Tools Technical Specialist
Microsoft Pty Ltd, Australia / New Zealand
Microsoft Visual Studio 2005 Team Foundation Server
Summary: An introduction to the concept of software configuration management including information about why configuration management is important, and the various branching and merging strategies. (6 printed pages)