Learning PHP 5 , by David Sklar. This book provides a gentle introduction to PHP for web designers and other nontechnical people familiar with HTML and the Web, but not with programming and databases.
Programming PHP , by Rasmus Lerdorf and Kevin Tatroe. Co-authored by the creator of PHP, Programming PHP is aimed at anyone looking to learn PHP. An exhaustive reference, this book covers all aspects of PHP, from basic concepts to advanced techniques.
Web Database Applications with PHP and MySQL , by Hugh E.Williams and David Lane. If you’re comfortable programming but have only just started using SQL, this book teaches you how to create an entire database-backed web site. Web Database Applications with PHP and MySQL works you through the entire process, including design, coding, and implementation.
These books are all published by O’Reilly Media, Inc.