As part of my personal conversion to Git, I read Swicegood’s Git book. It’s a decent introduction to Git and you learn how to do all the basic tasks as well as some more advanced topics. The examples are clear and well-paced.
I would have liked to see more about collaboration and workflow in a DVCS world, perhaps a few case studies: how is Git used in the Linux kernel development process; how a small, distributed team uses Git and GitHub; how a collocated team migrates from more traditional tools.
The book avoids discussing the lower levels of the Git object model, which is a reasonable choice for a pragmatic guide.