>Can't recommend a book, but I have a FoxPro friend who absolutely swears by SharePoint.

Really? I guess they must have done something right about Sharepoint now. I was "fortunate" enought to work with the first release and its beta version, then I used it again in 2003 for a project and after that I tried to avoid (successfully) any sharepoint development. It was quite painful to develop stuff with the first and second version of Sharepoint. I customized and hacked xslt left and right.
Apparently, there's a great demand for SPS development in the gov arena. That means more opportunities for Sharepoint enthusiasts:)
Some friends told me that SPS improved a lot since its early days. Im glad for them:)