[Atkinson 01] Atkinson, Leon. Core PHP Programming.
[Greenspan+ 01] Greenspan, Jay, and Brad Bulger. MySQL/PHP Database Applications.
[Lea+ 00] Lea, Chris, et al. Beginning PHP4. PHP for beginners.
[Lerdorf 00] Lerdorf, Rasmus. PHP Pocket Reference. A handy little book to have for a quick reference.
[Meloni 02] Meloni, Julie C. PHP Fast & Easy Web Development, Second Edition.
[Welling+ 01] Welling, Luke, and Laura Thomson. PHP and MySQL Web Development. A thorough discussion of PHP and MySQL.
PHP central: www.php.net
Tons of PHP scripts and articles: www.phpbuilder.com
Lots of good information: www.phpwizard.net
Online PHP manual: www.php.net/manual/en