Beginning PHP 5 and MySQL: From Novice to Professional by W J Gilmore   "I reach for this book when I want to get up to speed on something about PHP 5 quickly. With it, I can start coding and seeing results right away. The book covers a range of topics, the practicality of which can be best appreciated when you are faced with a real life project." Robert L Cochrane.
Learning PHP 5 by David Sklar
"I tend to review advanced, reference, and application titles because I've been using these tools for years. This is a good introduction for folks starting out with the latest version of PHP." Douglas W. Clifton.
Programming PHP by Rasmus Lerdorf
"Rasmus is the creator of PHP, so enough said." Douglas W. Clifton.
PHP Cookbook by David Sklar
"Dave also penned Learning PHP, thumbs up." Douglas W. Clifton.
The PHP Anthology, Volume I: Foundations by Harry Fuecks
"Being a pragmatist, I prefer solutions and examples to theory. Harry delivers both, and some theory for good measure." Douglas W. Clifton.
PHP Functions Essential Reference by Zak Greant
"This book, along with the goodies available online at New Riders, will help you turn the corner to expert-level PHP programming. Many usage examples." Douglas W. Clifton.