There are many places to put Google Adsense Adverts, personally I think there is only one good place to put Adsense on blogs.
The image shows a suitable heat map of where Adsense should go. The yellow represents content including the banner at the top. The green on the right is the navigational menus.
The red represents the ad formats. The long on at the top is the main banner, with the red square as a rectangular advert. The blue represent text links.
The reason this is on of the best, is that adverts continue down the page. With lots of content, adverts will mingle in and will help with your conversion ratio and earnings.