As we welcome Git as the new version control system for Drupal, there are probably many looking for good learning resources. This comes by way of chx:
lut4rp gave me a link today. I understood git. In minutes. Miracles! […]
The docs is at http://www.eecs.harvard.edu/~cduan/technical/git/
I agree that Git becomes much more usable when you understand what’s going on under the hood. Another great resource for this is PeepCode’s Git Internals PDF ($12 well spent).