Planet eZ publish
In the navigation tutorial, they show you a simpel way to use the switch() control to display different content based on a variable set in the $_GET array (URL string).
The second tutorial, Single-Page Password Protection, shows you quickly how to create a form that takes in a password and checks it against one hard-coded into the PHP script. If it validates, the "secret content" is shown.
Both of these tutorials are very simple, and, if you're not careful with them, could cause some security issues with your scripts. All in all, though, they're a good starting place...
If you frequent forums, you'd probably remember images in people's signatures that would display information about your computer. Such mysticism! This tutorial will teach you that, and more!
They show you step by step how to use the GD extension in PHP to update a pre-existing image (a PNG in this case) with the viewer's IP address dynamically. It's just a small bit of what you can do with GD, but it's a good introduction to what it looks like...
The intro tutorial starts at the very beginning, showing you how to put PHP code in your HTML pages. They show how to use variables and echo statement to make some simple output.
In the MySQL/Form tutorial, they assume that you have a bit of experience with PHP under your belt (though it's nothing a little searching through the manual couldn't fix). They create a form/script combo that checks to make sure you've entered in information and then, on submit, creates the correct SQL to put it into the database.
Neither of them include anything on installation, so you'll have to either set it up yourself or have a host that already has it installed to work on - though it's pretty easy to find those these days...
