Documentation call for help
The good news:
There is now some usable documentation for all the git commands except for the following:
git-archimport (Martin?) gitk (Paul?)
The bad news:
Some, if not most, of the command documentation is incomplete or possibly incorrect. Mostly it's a case of the documentation not keeping pace with changes in the code.
You can help by comparing the implementation of a command with it's documentation and producing a patch to fix or, at least, improve the documentation.