Tim Taubert recently posted on how he got involved with Mozilla. I intend to post about my experience at some point in the not too distant future but for now I wanted to highlight something from Tim's post:
I loved this feature but noticed that it was in an early stage and needed some fixes. I set up a Firefox build environment, went through Bugzilla to find open bugs, nagged people on IRC and was totally overwhelmed by the warm welcome and the appreciation of my work. This was something I did not at all experience when trying to contribute to other open source projects.Some areas are more or less difficult and some volunteers are more or less motivated, but if you love what we're doing with Firefox and want to be a part of it, there are a lot of us that would love to help you get onboard. If you're trying to get connected and don't have a starting point, please use me. I'm asa@mozilla.org and either "Asa" or "asadotzler" on IRC. Also, we're hiring.