As many people start using Git instead of SVN, here is quite some good guide to help switching from SVN to Git.
Git is a version control system developed by Linus Torvalds (the one who also created linux). It handles merges better than SVN does and preserves change histories much better. In addition, it is also used on many open source projects, nowadays.
Many Git projects are hosted at http://github.com/
Tutorial for Learning Git having an SVN Background: http://git.or.cz/course/svn.html