How to put AdSense ads in Blogger blog

Once you have an approved AdSense account, there are 2 ways to add AdSense ads in your blog

Method 1: Direct via Blogger Adsense gadget

Sign into www.blogger.com
Dashboard > Layout > Add a gadget > Add an AdSense gadget

Then in Layout, drag the newly added AdSense gadget to wherever you want and SAVE.

Method 2: Indirect via AdSense codes

Sign into google.com/adsense and click MY ADS at the top left, then +New ad unit, then select the ad unit you want.
After selecting the ad unit, at the bottom, click SAVE AND GET CODE

Now go to www.blogger.com
Dashboard > Layout > Add a gadget > HTML/Javascript gadget
Paste the AdSense code into the gadget
Drag the gadget to where you want and save.