In my opinion the easy way is to look through the github issues and pull requests and understand what's going on. From there, try reading docs and seeing what does / doesn't make sense and editing it. You pretty much always get feedback if you send a decently put together pull request.
Look for places the code might not currently be clear, and try to improve clarity without changing behavior.
Once you've done that kind of thing, sky's the limit as far as I am concerned. I'm working on understanding and improving the parameter parsing behavior at the moment.
Is there any sort of prioritized TODO list, either by difficultly or importance? And that's not so I can knock out some big feature and be the hero, but so I can whittle away at some of the more nagging edge cases and make some random developers day when things just work.
Even just making a little Rails app or script that re-produces the bug would be helpful. Writing a test case that's failing would be mega helpful. Fixing the bug would be incredibly helpful. :)
The issues page is the best you have for that, sort by popularity or something like that.
That's one of the only things I'm frustrated about - I wish there were a clearer list so that I didn't have to troll for tasks that need doing, or ask a core member on IRC/campfire
Look for places the code might not currently be clear, and try to improve clarity without changing behavior.
Once you've done that kind of thing, sky's the limit as far as I am concerned. I'm working on understanding and improving the parameter parsing behavior at the moment.