Our Android project will have an online repository hosted at GitHub. I’ve never used GitHub, though at work I use a local install of the similar Gitorious service. So far, we don’t have anything in the repo besides a GPL notice. The repository does have an integrated wiki that I have put some work into already. James and I discussed how to organize the repo and we decided we wanted to follow a professional approach that an actual project team working on commercial software might follow. Here is an excellent description of the model we will be using.
Basically, there will be four permanent branches. The first two branches, jon-dev and james-dev, are personal development branches that will hold snapshots of the project as we are working on it. We will keep our individual work separate in these branches so nothing one person does can affect the other. Here we also have the freedom to absolutely break the app while not affecting the snapshots in the next two branches. The code in these branches cannot be guaranteed to build into a perfect working app, but that is to be expected because this is the entry point for brand new contributions.
The third branch, develop, is where James and I will merge our work from our individual branches after we have gotten our code working the way we want. Snapshots in the develop branch should build into a relatively stable app, similar to nightly builds in a major open source project, though bugs may still be present.
The fourth and final permanent branch, master, is reserved for major releases of the app. Once the code in the develop branch has enough features implemented, and has been tested thoroughly, it can be merged into the master branch and tagged as a milestone build. Apps build from code in the master branch should be considered stable and without major bugs.
We can also create temporary hotfix branches as we need to. For example, if a bug is discovered in the master branch, we can create a branch to fix the bug, merge it back into master after the fix has been tested, and then delete the temporary branch.

From the blog Code Your Enthusiasm » WSU CS by Jon and used with permission of the author. All other rights reserved by the author.