At Slashdot, Michael J. Ross wrote a book review of the recent Apress title Pro Drupal Development. This book written by John K. VanDyk and Matt Westgate is really recommended if you are into Drupal module development.
As an avid Drupal fan, I already bought the book the week it was released and found it very helpful, not to mention enjoyable. The authors managed to put all the information you need to know into just over 400 pages. Most information is module development related, but they do cover the theming system enough to get you started.
Link to the review :
http://books.slashdot.org/article.pl?sid=07/06/06/1352210
