I've now read several books on SharePoint development, such as Developer's Guide to the Windows SharePoint Services v3 Platform , Microsoft harePoint 2007 Development Unleashed, and Programming Excel Services. I've found each of these books lacking, particularly the last two. The Unleashed book is more a reference than anything else and especially in the more advanced topics I really didn't find what I was looking for, which is not what you'd expect from an Unleashed title. The Excel Services book is a disappointment if you are looking for good information about Excel Services. If you want to learn to develop WebParts it is quite good however. In that sense the book has been completely misnamed. I hope that my next pick will be better (that said, two of the three books were given to me).