A few months back, I was sent a review copy of Drupal 5 Themes by Ric Shreves from Packt Publishing. I have been thumbing through it since, and despite some odd editing I have found it to be very easy to read. The examples strongly illustrate concepts through out.

I've started reading "Drupal 5 Themes" by Ric Shreves, available at PACKT publishing. I've gotten through the first couple of chapters so far but have found it easy to read. So far, I haven't learned much I didn't know--but it has put into a single place lots of information that I would have gone to several sources in the past.