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
SVN (Subversion) is very good and there is support for an Eclipse plug-in called Subclipse.
Git and SVN are both good choices, although I'd give SVN an edge since it's probably a bit easier to learn if you've never used a source control system before. As far as Eclipse integration goes, you'd be hard pressed to find a popular source control system that doesn't have an Eclipse plugin.
Find EGit Releases here : http://www.eclipse.org/egit/download/
Since Mar 2010 we did a release every 3 months, current release is 0.10.1 Next release is planned for end of Feb 2011 with Helios SR2.
If you're using a Mac, try out Versions. It's a tool for managing SVN repositories and working copies, and it's amazing (No... I don't work for them ;-) )They allow you to create repositories on your own computer, or setup a free one at BeanStalk.com
Subversive plugin for eclipse.
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.