Blogger Custom Domain

(taken from here)

Enter Blogger Dashboard > Settings image
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.

image
Log in to your domain registry account (Name.com, GoDaddy, etc.) image
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.
image
Now access your raw DNS record settings (aka “Total DNS”). image
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.