Pro Drupal Development, second edition
Widely praised for its in-depth coverage of Drupal internals, bestselling Pro Drupal Development has been completely updated for Drupal 6 in this latest edition, and there are even more tricks of the trade to help you further yourself as a professional Drupal developer. Assuming you already know how to install and bring a standard installation online, John K. VanDyk gives you everything else you need to customize your Drupal installation however you see fit. Pro Drupal Development, Second Edition delves deep into Drupal internals, showing you how to take full advantage of its powerful architecture.