Dougal Campbell has posted a review of a book targeted towards both WordPress beginners and pros - "Digging Into WordPress" by Chris Coyier and Jeff Starr.
I spent some time looking over it, And wanted to share my impressions. If you're in a hurry and just want the 5-second review: It's good, and it's got something for beginners and experts alike. If you want a more in-depth look, then please read on.
The book weighs in at 400 pages and eleven chapters covering all sorts of topics like themeing, security, installation of a fresh version of the code, plugins and custom development. There's also an archive included with the book with all of the code and plenty of examples to get you headed in the right direction.
You can find out more about the book - and order your copy - from its website.