Pro Git Resource

I remember hearing about Git and GitHub a few years back, but didn't pay too much attention. Now I see the Github community is blowing up. And I can see why. It's a great way for programmers to collaborate and share ideas. Although GitHub has some great documentation on getting started, I soon realized there were still some question I had about Git. I always like to dig a little further to gain a better understanding of the technology I am using. So with a little google searching, I stumbled across this free resource on the web, "Pro Git" by Scott Chacon. Also available in print.
http://progit.org/