Anonymous CVS access is available to everyone. If you would like to submit a patch, just mail in the diff or final edited files. If you are frequently offering patches, we can discuess giving you developer write access to the CVS repository.

Visit the CVS Quick Start for an intro to CVS.
If running from Windows, I highly recommend WinCVS.
I've created an online illustrated Step-by-Step pygame WinCVS guide.
CVSWeb access is available through this clickthrough button.