Digging into WordPress is a comprehensive guide to everything you need to know about WordPress.  I’ve had my eye on it for a while, but I was holding out to see the results of a competition to win a free copy of the print version (which includes a free e-book version).

Unfortunately, I didn’t win the print version, but I was one of three runners-up to score the e-book version. I am thoroughly enjoying reading it, and would recommend it to just about anyone dealing with WordPress.