Perry Marshall's is very good it gives a good understanding of what Adwords is all about. He takes you thru step by step. See my sig for a free sample.
Pasting from another thread: Go ahead for ppc classroom. Trusted, proven and surely the best one out there. Don't believe me? check out the link in my sig for a free report from one of its creators...amazing content for you to begin adwords
Hi Gakler You could consider buying my AdWords DVD set or if you're in the UK I run regular Google AdWords courses throughout the UK? Claire