Take a look at http://search.cpan.org/~rkinyon/ and see what you like. Helping can be anything from hacking on source to adding tests to fixing documentation to project management. As for experience, I took over my first CPAN module after just a couple years of Perl.
My criteria for good software:
Does it work?
Can someone else come in, make a change, and be reasonably certain no bugs were introduced?