In the talks and trainings that I do, I've been wanting a shorter, simpler reference site for people learning Git. The Pro Git book, being a full book, sometimes intimidates people trying to learn Git - I wanted something you could jump to specific commands quickly and was a bit easier to parse piece by piece. So, I give you my pet project from the EuRuKo/Amoocon trip we just got back from:
It takes the most used Git commands, groups them into commonly needed tasks and has that reference table available on each page. You can either use it to read about a specific command if you need a refresher or you can read through it as a continuous tutorial.
Hope you find it helpful.