Here is a list of some of the most popular sites for mySQL and php help. Please leave some comments with some more sites to add to the list.
Official Web sites:
PHP: http://www.php.net
mySQL: http://www.mysql.com
Tutorials and Articles:
W3Schools: http://www.w3schools.com
Pixel2life: http://www.pixel2life.com/tutorials/php.php?tut=10
The Scripts.com: http://www.thescripts.com/serversidescripting/php/
DevShed: http://www.developershed.com/Server_Side/PHP
phpBuilder: http://www.phpbuilder.com/
Zend Dev Zone: http://www.zend.com/developers.php
SitePoint PHP & mySQL Tips: http://www.sitepoint.com/subcat/98
CodeWalkers Tutorials: http://codewalkers.com/tutorials.php
PHP freaks: http://www.phpfreaks.com/
PHP Intro (written by the creators): http://www.zend.com/zend/art/intro.php
Script/Software/Extension Repositories:
PHP Class Repository: http://www.phpclasses.org/
HotScripts: http://www.hotscripts.com/
WeberDev Code Examples: http://www.weberdev.com/
PEAR (+PECL): http://pear.php.net/manual/en/about-pear.php
AMP Bundles (Apache/mySQL/PHP)
PHPDev: http://www.firepages.com.au/
Sokkit (formerly known as PHPTriad): http://www.phpgeek.com/
WAMP
WAMP Server: http://www.wampserver.com/
I hope that these help you with you learning process with php and mySQL.