The Australian AdSense team has put together a step-by-step guide to optimising your AdSense performance. We cover:

1. Analysing your webpage
2. Creating custom channels
3. Determining best ad design and placement
4. Maximising ad units on a page
5. Tracking and measuring your results

For more information on AdSense optimisation, visit the Help Center guide - https://www.google.com/adsense/support/bin/topic.py?topic=8443