The LearnList

www.php.net/
www.w3schools.com/php/
www.phpfreaks.com/
www.tutorialized.com/tutorials/PHP/1
http://video.google.co.uk/videosearch?q=php+tutorial
www.hotscripts.com/PHP/index.html
http://devzone.zend.com/manual
www.killerphp.com/
www.phpbuilder.com/
http://tizag.com/phpT/
http://hudzilla.org/phpwiki/
www.squeekmachine.co.uk/code.php?s=5
www.phpvideotutorials.com/

PHP 6 and MySQL 5 for Dynamic Web Sites (Paperback)
Programming PHP (Paperback)