I really like his book "The Digital Photography Book" and I got a lot out of it. For that book, it helps if you're not an absolute beginner.
If you are an absolute beginner, you may want to look into "Digital SLR Cameras & Photography for Dummies" by David Busch (looks like an updated version of this book comes out a week from today!). Busch has a bunch of other books that are also likely very good should you wish not be to associated with the "Dummies" series...
Whether you are a beginner or a more experienced photographer, I highly recommend "Understanding Exposure" by Brian Peterson. This book is older and some of the references are to film cameras, but the general principles are the same and it is just a great book on the foundations of exposure which are important to have a grasp of. Without light, we wouldn't have photography, no? (Brian has another book called "Learningn to See Creatively" that is more of a composition book, but also very good.)
One other thing--depending on what kind of camera you have, there is possibly/probably a book written for your particular model that goes into more detail than the manual. So, if for instance, you have a Canon Rebel XTi, you can check out the "Canon EOS Digital Rebel XTi/400D Field Guide" by Charlotte K. Lowrie. I have found these books are very helpful in explaining what your specific model can do. Kelby does a good job of this but is not model-specific.
I have always lusted after, but never plopped down the money for "Light and Lens: Photography in the Digital Age" by Robert Hirsch. This book is kind of pricey, but is said to be a cross between a textbook and an artbook, complete with exercises as if you were taking a photography class.
Enjoy your new camera, don't forget to look into some cool lenses and good luck!
