Ha... Haha... you're funny.
um... at the moment? Some of it's documented on the development wiki, but you'll probably have to poke through some header files at the source code x-ref @ mxr.maemo.org for some of it. I haven't checked the dev wiki recently, but last I saw, it was lacking in depth mostly, and breadth to some extent as well. If you have specific D-Bus calls that you're looking for, and can't find them, I or someone else may be able to tell you off the top of our heads.