Check out Mastering Windows SharePoint Services 3.0. This book could be the comprehensive WSS 3.0 reference guide. And it will be an interesting read.
C.A. Callahan (the author) is a friend of mine and she has been working her a** off to get this thing done and do it well. And she didn't have a very big a** to start with. (Sorry C.A.--couldn't resist). If there is something in there, you can bet your sweet bippy that it's in there for good reason and what she says will be right.
In the interest of full disclosure, I should probably mention that I wrote one of the chapters for the book. Nowhere near enough to get my name on the cover, but I think I get mentioned in the credits somewhere. Despite that, this is an awesome book that will be incredibly useful for anyone who has to work with WSS.
BTW--check out her blog for more useful info. It's in my links list on the right hand side, or you can get to it Here.