Repository layout

I was wondering if anyone had some advice for structuring a repository.

We're going to have multiple project teams working on various bugs in
various states of funding and completion. The final product is supposed
to be kept in near pristine condition at all times. I don't think we can
manage this by just allowing everyone to commit to the trunk and tag
releases for testing purposes. I think each project might need its own
branch where the users can work without being getting tripped up by
other projects. Then when the project's done merge the latest from the
trunk to the project branch and test a build off of there until it's
approved for being merged into the trunk (this would basically be a
strategy to make each project a single pre-tested commit to the trunk).

Any ideas on a structure to best support this?

James Oltmans
Software Engineer
Bolo Systems, Inc.
  <http://www.bolosystems.com/>
(303) 987-2238 x 107
(720) 212-0687 Direct
joltmans@bolosystems.com