How to rename a Build Type in Team System (and a suggested naming convention)
I suppose this might be in the manual, but...
If you want to rename a Build Type that you have created in a Team System Project, you need to open the Source Control Explorer window, dig down into the TeamBuildTypes folder under the project, and rename the folder that corresponds to the build type you want to change. After you check in that change, refresh the Team Builds folder in Team Explorer and you'll see your newly named Build Type.
Remember to change any scheduled tasks you may have created to run your builds automatically.
One more thing about naming Build Types - because we like to have an email sent out to the team members after a build, we have found that a naming convention for the build types helps make it easier to easily recognize and organize the build notifications. We use a standard that includes the environment, the Team Project name, and the sub-solution as the name of the build. So we have build names like
DEV Slam Customer Website - This builds the CustomerWebsite.Sln in the $\Slam\DEV branch.
QA Slam Customer Website - This builds the CustomerWebsite.Sln in the $\Slam\QA branch.
DEV Slam Monitor Service - This builds the MonitorService.Sln in the $\Slam\DEV branch.
QA Slam Monitor Service - This builds the MonitorService.Sln in the $\Slam\QA branch.
Having the project name in the build type helps because if you are a subscriber of lots of different builds for different projects, you cannot tell by looking at the email (other than this naming convention) which project the build is from.