In my continued quest to increase my Drupal 6 knowledge I picked up this book on module development for version 6. 
Over all this is an excellent book. This is definitely targeted more at a developer which is probably why I liked this book. I think the author does a great job of explaining the basics of how Drupal works and specifically covers a lot of information on hooks which are key to understanding how to accomplish most any task in Drupal.
The modules that are developed through the book are well chosen because they cover the essential pieces of module development and at the same time allow a little time for some more advanced topics. I was surprised at how well the theming code was covered in this book. Most module development books usually leave all the user interface development out but this book shows how you implement your module in a way to take advantage of the theming capabilities in Drupal.
Over all this is a great book and if you are familiar with Drupal a great way to either learn about module development or get up to speed on some of the Drupal 6 changes to modules.

