• File I/O in PHP - File access in PHP is much simpler than people seem to think.
• Anti-Automated Registration - Have you ever seen popular sites that block automated registrations with an image that has some garbled string? These are extremely hard for a computer to read, but they are extremely easy to generate.
• Creating Dynamic Text Images - PHP has the ability to create on-the-fly images with the use of GD. This tutorial will aid you in creating a dynamic image with a TrueType Font (TTF) string on it.
• Installing PHP on Apache 1 - Installing PHP on an Apache server is a lot easier than most people seem to think. It takes only a few minutes to do. Follow these easy instructions...

They have these tutorails and many, many more, so be sure to check them out...