Google AdSense is a program run by Google through which website publishers in the Google Network of content sites serve text, images, video, or interactive media advertisements that are targeted to the site content and audience.
In case you already connected your website to Google AdSense, follow this tutorial to Show Google AdSense on Your Blog.
To connect your website to Google AdSense:
Go to https://www.google.com/intl/en_uk/adsense/start/ and click Get Started.
Enter your website domain, email address and click Save and Continue.
Note: If you don't have a Google AdSense account, it will be created at his point.
In the Home tab, copy the code under Your AdSense code. This is your unique verification code.
Go to your Website Editor, click Settings, and select Plugins from the drop-down list. Click Manage, then Add New Plugin and add Google AdSense.
In the Application ID field, enter the code snippet you copied from Google AdSense. Insert the code, Enable it, and click Save.
Publish your website to update it with the changes you've made.
Once you Publish the website, go back to Google AdSense and check I've pasted the code on my site checkbox, then click Done.
If all the steps were done correctly, you should receive this message which will tell you that the website is under review.
Once Google approves your website, the ads will be shown automatically, and Google AdSense will decide the best location for the ad.