On the PHPEveryday.com site there's a recent tutorial with an introduction to Smarty, a popular PHP-based templating engine.

When doing web application development, it is important to make the separation between display design (presentation) work and creating application. Simply, you can create content before without having to consider display (presentation layer). Or, you can design the look without the care of application code. This is role that Smarty Templates want to play.

They look at getting it installed, some of the basics you'll need to know and a few more complex features like arrays, objects and variable modifiers.