The first things to do are probably to request a Dreamhack, and then start having a look at Bugzilla

See, I wouldn't suggest that. I would suggest getting a Dreamhack and then looking at the code first. Just looking at something where you know what it does (for example htdocs/userinfo.bml) and reading a Perl book to figure out what's going on in there, asking in IRC when you're stumped. But that's basically different styles in how to tackle starting to program.

http://tinyurl.com/nalrs8 is the 'effort-minor' Bugzilla search. Handy link :)