If you want to show the Ads between your post but chose not to do it while initially signing up for AdSense, the first step you go to your Template and click on the Page Elements tab.  Then, in the Blog Posts sections, click on ‘Edit’.  A Pop-Up window will open with options to configure your blog posts.  Check the box next to “Show Ads Between Posts.”  You must be signed up for AdSense before you can check this box.  Once you check this box you will see the configuration options for your ads.  You can then select how often you would like ads to be sown after your posts.

For example, if you want ads to be displayed after every post, select “1” from the Drop-Down menu.  Note that AdSense policies limits you to a total of 3 ad units per page and Blogger will automatically prevent you from going over this limit.  You can then select your ad format and colors.  Once your have finished configuring your ads, click on the orange “Save changes’” button in the bottom right corner.