1. Visit the Adsense website at Google.com/adsense. Sign in with your Google account.
2. Click the 'My ads' tab. Then click the 'Get code' link for the Adsense banner you want to add to your blog.
3. Highlight the entire block of code using your mouse, and then right-click it and select 'Copy.'
4. Open your WordPress dashboard page and sign in with your account credentials.
5. Click the 'Editor' link under the Appearance heading on the left side of the screen.
6. Click 'Header' on the right side of the screen to open the header file.
7. Scroll down until you see this tag:
Click to insert your cursor right after this tag, and then right-click and select 'Paste' to paste your Adsense banner code into the header file.
8. Click the 'Update File' button to save your changes.