I am taking two web development classes this Fall at Saddleback Community College. One is about AJAX and the other one about MySQL and PHP. Since the syllabus of both classes doesn't quite fit my interests, I am going to spice up AJAX with learning JQuery and MySQL/PHP with learning CodeIgniter. The following list has several links that I think will help me and possibly you get started with CodeIgniter.
The list includes everything from a direct link to the CodeIgniter site out to sets of tutorials covering basic usse, integration with Doctrine and various general PHP tutorials that could also be handy for reference. He also includes a link to the HTML and PDF versions of the framework's manual.