Write an article based on this summary:

Log into your WordPress dashboard. Log into your AdSense account. Build your ad in AdSense. Click "Save and get code. Add the code. Review your ad. Publish or update your post.
This method assumes you already have a WordPress site that you can edit, as well as an AdSense account. You must do so in a separate tab on your browser. In AdSense, click "My Ads" at the top-left of the page. To do it, click "New ad unit," and design your ad in the dialog box that appears. " Do it as soon as you are finished editing your ad. Copy the code for the ad in the dialog box that appears. To add it, on your WordPress dashboard, navigate to the post or page editor for the post or page you wish to add the AdSense ad to. In the "Text" editor, paste the code among the HTML for the post where you want your ad displayed. Make sure you are looking at the "Text" editor, and not the "Visual" editor. It will say in the upper-right corner of the editor box. After you paste the code, in the upper-right, click "Save Draft," and then click "Preview" to make sure your ad displays as you want it to. When you're happy with how it displays, you may publish or update your post or page by clicking "Publish" or "Update," whichever button appears, depending on whether it's a new post or not.