My app code is starting to get unmanageable and I want to start source control, primarily because I need to branch my code.
What are some good systems that you have
I'll put in another vote for subversion. It should be easier to learn than git, and will easily provide all you need.
As for the eclipse integration, you can choose between two different plugins: Subclipse or subversive. You can find lots of interesting debates on the net about which is the better one. I'm personally using subversive because it's a bit more intelligent about trunk/branches/tags handling in svn.