I am a programmer, and I want to help, what can I do?

There are a number of projects being worked on, you might want to check out the gnome-status CVS module from the CVS to see a list of projects that people have identified as needing work.

A good rule is that you can always improve the robustness of code, improve the user interface, make the code simpler, make the user interface better, make sure applications are properly internationalized and localized.