On the CSS-Tricks.com website Jason Lengstorf has put together a tutorial on the creation of your own custom content management system by combining PHP and MySQL.

It's safe to say that nearly every website that's up-to-date these days is using some form of content management system (CMS). While there are a ton of great free options that provide us with a CMS to power a website (Wordpress, Drupal, etc.), it doesn't hurt to peek under the hood and get a feel for how these systems work. [...] This class is intended to give you a feel for how PHP and MySQL interact together, and to show the basics of a CMS.

He first builds out a main CMS class for his display and database functions to live inside, then moves on to creating the actual database (with one table) and how to save and retrieve that information back out.

You can also view a demo of it in action and download the files to get started right away.