To map your registered domain to your Blogspot account, follow the steps below:

1. Login to Blogger and update the information on your Settings | Basic tab
2. Find the area for "Publishing," and click the link to add a custom domain.
3. Then, click on "Switch to advanced settings."
4. Enter in the URL for your custom domain (i.e. www.your-domain where your-domain refers to your domain excluding the www) in the text box provided, and click Save.
5. Click here