You hear a lot about GIT in the Ruby and Rails world - which makes you wonder: What is so bad about Subversion?
Turns out, nothing. But GIT has some definite advantages which are clearly and succinctly explained in the book. It doesn't assume previous knowledge about version control systems, which is nice for people just getting their feet wet with this kind of software.
Instead of simply telling you how to do something, it also explains why you would want (or need) to do it. And what problems could arise. And how to work around them.
It also explains how you can start using it yourself, even if the rest of your group is still using Subversion. It turns out that GIT can play quite nicely with that popular piece of software - which should encourage hesitant people to take the plunge.