It is a little spartan at the moment, and it appears to be incomplete (which should not be surprising at this point). But it seems to be well-structured.<p>I have never written non-trivial amounts of documentation, so I can only guess, but I have the gut-feeling that structuring documentation well is pretty hard, much like interface design (both for APIs and UIs) is (to me, at least) very hard. So having a well-structured but incomplete Wikibook as a starting point is probably <i>a lot</i> better than vice versa. ;-) The parts that are there are well-written.