How to show Adsense Ads in your Blog and Earn Money : Step by step guide by Google Support

Advertise on your blog

With Blogger, you can make money with your blog by showing AdSense and other ads on your pages.

Note: Advertising on adult blogs is prohibited. Learn more about the  Blogger Content Policy and Terms of Service. and Terms of Service.

Sign up for AdSense to show ads

1. Sign in to Blogger.
2. In the top left, click the Down arrow .
3. Click the blog you want to run ads on.
4. In the left menu, click Earnings.
5. Click Sign up for AdSense. If you don’t see the button, it means your blog might not qualify for AdSense. Check the Adsense Eligibility Test to find out why.
6. Fill out the form with your Google Account or create a new one.

Note: It can take at least 48 hours for your application to be reviewed.

Show ads between your posts

1. Sign in to Blogger
2. In the top left, click the Down arrow .
3. Click the blog you want to show ads on.
4. In the left menu, click Layout.
5. Depending on your template:
   • In "Blog Posts" under "Page Body," click Edit.
   • In "Blog Posts" under "Main," click Edit.
6. In the window that appears, check the box next to "Show Ads Between Posts."
7. Choose the ad format, colors, and how often the ads should appear.
8. Click Save. 

Show ads in the columns

1. Sign in to Blogger.
2. In the left menu, click Layout.
3. Click Add a Gadget.
4. Select the AdSense gadget and click Add .
5. Configure AdSense and click Save.
6. In the top right, click Save arrangement.

Show ads from other ad services

1. Sign in to Blogger
2. In the top left, click the Down arrow .
3. Click the blog you want to show ads on.
4. In the left menu, click Layout.
5. In the area where you want to place the ads, click Add a gadget.
6. In the window that appears, under "Basics," find HTML/Javascript and click Add .
7. Enter a title (optional).
8. Copy and paste the code from the ad service website into the content section.
9. Click Save. 

See your Blogger earnings report

1. Sign in to Blogger
2. Click the blog you want to see a report for.
3. Click Earnings.
4. Click Visit AdSense for details of my earnings.

See the AdSense glossary to learn what each term on your report means..

What to do if AdSense isn’t turning on

1. Sign in to Blogger.
2. In the top left, click the Down arrow .
3. On the Blogger dashboard, click the blog you want to put AdSense ads on.
4. In the left menu, select Layout.
5. Under the AdSense gadget, click Edit.
6. Click Save.
7. Repeat Steps 4 and 5 for every AdSense gadget on your blog.
8. At the bottom of your "Blog Posts" gadget, click Edit.
9. Click Save.
10. In the top right, click Save arrangement.
11. To check that your account is still active, go to Adsense.

Set up an ads.txt file

If your blog is monetized with third-party providers or you’ve manually integrated AdSense in your blog, you will need to manually set up the content of the ads.txt file.

1. Sign in to Blogger
2. In the top left, click the Down arrow  .
3. Click the blog you want to set up an ads.txt file on.
4. On the left, click Settings.
5. Under "Settings," click Search preferences.
6. Under "Monetization," find "Custom ads.txt" and click Edit.
7. Click Yes.
8. Copy the settings from your third-party monetization provider and paste them in the text box.
9. Click Save settings.
10. Optional: To check the content of your ads.txt file, go to http://<your blog address>/ads.txt.

Note: If your blog is not monetized, or it’s only configured to use AdSense using the Blogger-AdSense integration, then you do not need to manually set up ads.txt. Blogger will do this for you. Read more about  ads.txt for AdSense.

Read More Here : https://support.google.com/blogger/answer/1269077?hl=en