It's no secret that Git, as a source code control tool, has become quite popular in 2008, in part boosted by the success of the socially oriented github.com Here is a list of six resources that will help you get more comfy with Git, whatever your current knowledge of the tool. Let me know if you think that, after reading these six documents, you can still point to a few stones left unturned.
A to-the-point document, created by Mark McBride, that covers several scenarios and for each scenario, shows how Git could make your life easier if you are not using it yet.
A concise guide for the absolute beginner who wants to hit the ground running. Go through the exercises and you will end up with a pretty good picture of what Git can do.
A quick cheat sheet: start with the section corresponding to your role (individual developer, contributor, integrator...) You will not learn a lot about Git's philosophy, but you will certainly get the job done.
Ben Lynn wrote a whole book covering not just cloning and branching but also some precious recipes: What to do when something goes wrong? What if my commit is too big? Remote access magic, history digging...Even Git's shortcomings and their workarounds are covered.
John Wiegley makes a convincing case that approaching Git from a 10,000 ft level is not the best way to understand the tool's philosophy. Rather, building your knowledge of the tool based precisely on the very concepts that it uses make it much easier to get an overall grasp of Git's world.
Using source code control has always been an effective tool to maintain a web site, especially avoiding these "Uh-oh I clobbered something I shouldn't have" moments. But Git is particularly well suited to this task, due to its self-sufficient nature. Daniel Miessler shows us how to do just that using Git hooks.