That's great! Thanks, Patrick. I've added that to https://www.mediawiki.org/wiki/Berlin_Hackathon_2012 and I've added a skeleton at https://www.mediawiki.org/wiki/Git/Tutorial . It seems to me that people need help in the following areas:
Basics: * setting up Git * submitting a patch * commenting on a patch in Gerrit * merging a patch in Gerrit
Collaborating: * project ownership * tagging * branching * deployment * code review guidelines (quick overview)
Troubleshooting: * bisect * amending (rebase vs multiple commit) * merge conflicts
and we have 6 weeks before the event, so we should start prepping the tutorial now, improving documentation on mediawiki.org along the way. I'll coordinate with you, Patrick, to start on that.