How do you manage your branches in Bazaar?

We’re giving Bazaar a try today at work and we’re wondering how some people manage their branches in a project. We’ve decided to keep a pristine branch on our local development server and do our operations via sftp or rsync. Generally our projects are structured as such:

/project
-/branches
-/tags
-/trunk

Our dilemma is that when we create our local branches off the trunk (with bzr branch) we’re not really sure if its kosher to push that back as /project/branches/paulcs_branch or just keep it locally and merge into the trunk when we’re done. We’d like to have eachothers’ branches available off the “pristine” copy if possible. Does this make sense? How then do you handle merges into the trunk when a branch is complete using this method.