An Animal Trainer's Introduction To Operant and Classical Conditioning
If you want to get into the technical side of things, then here's a good introduction to operant conditioning, which is what clicker training is based on.

Cat-Clicker Mailing List
A great group of people, this mailing list has helped me tremendously in my clicker training efforts.

Clever Cats! Clever Cats! new
Photos and instructions on how to train cats to stay, come, give paw. Not exactly how I'd train, but I've found every cat is an individual and what works for one doesn't always work for another.

Clicker Solutions
Great articles and a FAQ about clicker training. A list of recommended reading; aimed at dogs, but much applies to cats, too. A mailing list devoted to clicker solutions.

Clicker Train
While it's difficult to tell when this site was last updated, there are several articles on clicker training, including beginning articles.

Clicker Training - A Brief Introduction
What clicker training is, how to start, the advantages of clicker training, and definitions of terms used in clicker training.

Clicker Training Fast Start
Simple steps to get started with clicker training.

Clicker Training Lessons
Although this site is geared towards dog, there are eleven basic clicker training lessons, as well as information on what clicker training is.

An Introduction to Clicker Training
Good explanation of why a clicker is better than simple verbal commands.

Gary Wilkes' Click and Treat Training
Articles on dog training and behavior (some of this applies to cats). Home of my favorite clicker, the Mega Clicker.

Karen Pryor's Clicker Training
Get clicker gear. Read articles on how to clicker train a variety of animals. Find out how you can bring clicker training to a shelter near you.

What is Clicker Training?
Basic article explaining what a clicker and clicker training is.