There are quite a few ways to help out this fine project:

Help test new releases
Join the ugr-testing team on lauchpad and you'll get all the information you need.  Be sure to file complete and accurate bug reports with the appropriate project. 

Help with artwork
Design logos and wallpapers for UGR.

Help put together packages
Many people who are skilled in Debian/ Ubuntu packaging are needed to package the different parts of GNOME and other miscellaneous things.  Join the ubuntugnome team on launchpad, and find a sub-project that needs some work.  View the guide to Ubuntu packaging and using Bazaar with Launchpad, upload your work, and propose a merge of your branch into main. 

Help organise Launchpad
The various releases, blueprints, and milestones need to be plugged into all of our Launchpad sub-projects, and bug reports need to be dealt with.  Join the ubuntugnome team on launchpad, and find a sub-project needing some attention.  

Figure things out
There are quite a few things that need to be figured out.  Post your findings on the ubuntugnometeam mailing list.  

Note: Our policy on team membership
Anyone may join the UGR testing team on Launchpad.  We don't accept new members to the main UGR team without reason, due to security concerns. Please contribute to the project by helping with bugs and blueprints and proposing mergers with our code. Then, apply to join the team.