I just register a free domain for my other blog and I confess that it was nothing easy to setup! I found many references on Google and had to add more to get everything to work correctly. Something like that, ok here easy guide..
First, you need to find the free domain. There are many blog for this purpose, but I choose Blooger. Between the link shown and enter the address you want to assign to your blog. In my case was allinfo4u. Click check availability and the fields appear available see screen shoot.
Choose what name you like and click continue to registration. Make your registration, and wait for an email confirm, or if u not have account you can register here :Co.Cc - Free Domain
Blogger are hosted on Google servers and need to be directed to the new domain. The first thing we should do is to enter the Control Panel of the site where the domain was registered (in our example is co.cc) and change the DNS.
1. click host then type www.yoursite.co.cc
2. click TTL choose 1D
3. click CNAME field and type ghs.google.com. then click Set up.
Generally, it takes about 48 hours for the CNAME changes to propagate over the Internet. oh don't forget to tick redirect. see a picture
From now on, your blog will be directed to the new domain! Click the link below
*. see official custom domain here