Blogtimize - Optimize Google's AdSense

This "heat map" is only used as a guideline and illustrates the ideal placement of your Google ads.
Blending your ads will increase the likelihood that your readers will see and click on your ads. Draw attention to your ads with bold colors while leaving the background and borders of your ads the same color as the background of your template.

There are a number of choices for the sizes of your ads and there placement, notice other peoples blogs and you'll see what other people prefer. The Format gives you all the choices available to you, also view the options on the Ad Format page. Colors will give you a choice of color for the Border, Title, Background, Text and URL. Choose from one of the pre-designed color palettes, by clicking on the color, you will see it change in front of you on the left hand side of your screen.

• Header - A popular choice is using a 728 x 60 for the header
• Body - A popular choice is a 300 x 250 Mediium Rectangle
  
• Sidebar - A popular choice is a 160 x 600 Wide Skyscraper

You will want to experiment with your ad placement and colors to see what works for you. You can read more here at the Google's AdSense Help Center for ways to Blogtimize and Optimize your Google's AdSense.