After working as a molecular biologist at the bench for many years, I lost my job last year and am thinking about a career change. I've been using open-source software and doing Linux system administration since the mid 90s, and have written/improved some small shell/Perl/PHP scripts, and am very comfortable building from source, but never progressed to creating non-trivial programs de novo. I want to move to actually learning real programming skills and contributing back to the community, with the possible eventual goal of getting into bioinformatics as a career in the future. I'm a stay-at-home dad now, so I have some time on my hands.

I've done a lot of research on languages, and have settled on Python as my major focus for now. I'm set up on GitHub, but haven't forked anything yet. I've looked around OpenHatch some, but nothing really grabbed me. I've heard the advice to work on what you use/love, but that category is so broad that I'm having trouble finding any one thing to get started on. What are your suggestions for getting started? How do you pick a project that will welcome your (possibly amateurish) help? With a fairly limited skill set, how do you find a request that you can handle? What are common newbie mistakes to avoid? Any other advice?