I’m a huge fan of the Google AdWords learning center that has plenty of Breeze Demos.

AdSense has 4 demos that I’ve found, as they’ve just added a payment Demo. I’m not a huge AdSense publisher, but as I’m an AdWords advertiser I like to keep up with what’s going on the in contextual world.

Here are the Breeze demo’s I’ve found so far:
Getting Started with AdSense Demo
Payment Demo
Ad Code Demo
AdSense Optimization