http://www.google.com/support/adsense/bin/static.py?page=tips.html&hl=en

Each week, we'll take a closer look at different areas of optimization, including how to effectively track your performance, design attractive ads, and engage users with the full gamut of Google products. Ready to optimize? Stay tuned to the AdSense Blog and AdSense Calendar, where we'll feature daily posts and tips to get you on the road to a site that rocks--and generates revenue.

--
Pretty sweet :)