The PHP Cookbook by David Sklar and Adam Trachtenberg is an excellent reference manual for PHP. I’ve meddled with PHP a bit in the past, but now after going through the book, I feel a lot more confident about my ability to use PHP and know that if I’m stuck there will likely be a recipe in the book that will help me out. The book, like all the O’Reilly cookbooks, is organized into problems and solutions, which are clustered into topic chapter, such as Web Basics, Database Access, et cetera. I read it front to back because from past experience I’ve found that doing this lets me stumble across new information I wouldn’t have, and this book was no exception.
The book had well thought out examples and often showed multiple ways to solve the same problem (and commentary on the pros/cons of the various approaches). I bookmarked a dozen or more pages with recipes I want to try out to improve aspects of my website.