and don't just do it test test and test... as you can never know what is the best place until you test. make a habit of testing
You can try to use Adsense's channel to test the results, the CTRs. I will suggest put the ads inside the text. Use different ads placement, ads size, and ads color in different pages. Use channels to track the results separately for around 2 weeks time. You may find that certain pages give you a better Adsense earning and CTRs. Copy that page's ads format to the rest of the pages. This is how you maximize your Adsense earning.