The documentation is being added at present. The best way to influence which docs get written first is to let us know on the mailing list.
You can get help on TurboGears from the mailing list, by asking questions and searching the list archives. (There's also an announcements mailing list if you just want to keep up with new development.)
Most of the techniques you need to use in TurboGears come directly from the projects that are included with TurboGears. That means that you can get great support from the established mailing lists for those projects:
MochiKit mailing list for MochiKit JavaScript related questions.
Kid mailing list for Kid template related questions.
CherryPy-users mailing list for questions about how to use CherryPy. Since this is where TurboGears code is most visible, your best bet may be the TurboGears mailing list for these questions. This is still a good list to subscribe to, though, because tips that come up here are often relevant to users of TurboGears.
CherryPy-devel mailing list for talk about improving CherryPy itself.
SQLObject mailing list for questions about using SQLObject to work with your database.