Blogger Custom Domain

(taken from here)

Enter Blogger Dashboard > Settings
Under Publishing section: Enter your custom domain in the first box complete with the www prefix. Check the redirect box under it. Save those settings. You’re done with the Blogger side.
Log in to your domain registry account (Name.com, GoDaddy, etc.)
First, especially if you ported your domain from another registrar like me, make sure that your domain is set to use your new registrar’s Nameservers.
Now access your raw DNS record settings (aka “Total DNS”).
Enter IP Address 216.239.32.21 as ARecord (@), this is a primary Google endpoint.
and ghs.google.com as CNAME (for www)
Save Domain registry settings.
You’re done.
Fire your page.