Attached Link: http://www.amazon.com/Wards-Photoshop-Productivity-Toolkit-Time-Saving/dp/0782143342/ref=sr_1_1?ie=UTF8&s=books&qid=1277024677&sr=1-1

Take a look at the book in the link. It's dated 2004, but still valid AFAIK. It has a CD with a lot of actions on it, but the book goes into quite a lot of detail about what actions can do, how they're made, and so on. The 'Look Inside' feature of Amazon gives you the first chapter too look at.

Steve