Don't look for a project to contribute to. Pick a real problem you have - maybe a bug you can reproduce or a feature you'd like - and fix it. If you approach a

Don't look for a project to contribute to. Pick a real problem you have - maybe a bug you can reproduce or a feature you'd like - and fix it. If you approach a maintainer with a stackoverflow-like question "I'm trying to achieve X, I got up to point Y and am stuck on Z", it's likely they will point you in the right direction. If you still feel like you want a specific project and you don't necessarily have a problem to solve, go into their bugzilla/issues-db and start helping moving all the bugs forward: try to reproduce them, ask users for more info, fix the tags, etc.