I figured this out eventually. However, when I first switched to git (and before I had tools to show my branch in my prompt), I managed more than once to make 3-4 commits on a detached head, and finding out how to fix that between the documentation and/or Google was essentially impossible. Once I simply gave up and re-did the work. The other time I figured out how to fix it, at the cost of about 3 hours of research and (eventually) questions on the IRC channel.

It's a powerful tool, and the docs are fine if you are an expert who already knows what you're looking for. I'll submit that it can be incredibly hard for a noob to learn to use correctly.