Many community projects, and specially those headed with a single developer or two, don't make things easy for potential contributors either. This is a problem known in the free software community.

Proposal: once you ave decided to which project you want to give a hand go there and try to find a task to do without asking them, looking at their website, wiki, bug tracker, roadmap, mailing list archives... If you find a "Get Involved" or a list of open tasks, excellent. If not, probably the guys are too busy and looking not much beyond their releases. Consider starting helping them by putting a Get Involved page in place.