If you bought your domain name from Blogger, you won't need to create a CNAME record.
That advice was written to advise the use of the Blogger "Buy a domain" wizard, which provides non BlogSpot URLs for Blogger blogs, through a simple 15 minute purchase process. In September 2012, that simple process changed, slightly.
If you are trying to re publish your blog to a non BlogSpot URL - and you are seeing an "Error 12" / "Error 32", or similar message in the Publishing wizard display - you need to add a second "CNAME" address to your domain.
The new "CNAME", added in September 2012, allows you to verify ownership of the domain to the Publishing wizard. Any time you re publish your blog to a non BlogSpot URL, you have to verify ownership. This prevents people who are not you from deviously publishing their Blogger blog to your domain.
If you are reading this, and you are the owner of any website which provides advice on how easy it is to purchase a non BlogSpot URL for a Blogger blog - and part of your advice mentions
If you bought your domain name from Blogger, you won't need to create a CNAME record.Please, edit your instructions to reflect the reality of domain ownership verification.
If you are reading this, and you know of a blog or website which provides the confusing advice
If you bought your domain name from Blogger, you won't need to create a CNAME record.let us know, below.
Try and reduce the confusion, when people have to re publish their blog, after using the Blogger Publishing wizard - or possibly after buying directly from a registrar. Help us, to help you.