If you're new to PHP (or just want to move up beyond the "beginner" level in your code) you should check out the PHPKnowHow.com site. It offers a complete (and growing) guide to some of the basics of using PHP "in plain English".

PHPKnowHow is a web site about PHP. Our objective is to teach you PHP using simple explanations and digestible examples. If you are new to PHP, begin with Role of PHP in Web Applications. [...] his site is for sharpening your PHP skills. Whether you are an absolute beginner or know bit of PHP already, you would find material here useful.

The main categories right now include content about the basics of the language, working with the PHP configuration (php.ini), using the GET and POST superglobals and a section about MySQL integration.