That being said, many of the domain registrars out there love to either through lots of extras at you (GoDaddy) or often don't provide the tools that you need to manage your domain effectively. Because of this, we've arrived at Namecheap as the domain registration provider that we use and recommend (we don't receive any compensation from them). Their prices are good, their tools are robust, and there is very little upsell.
The problem? Their interface is clunky at best. So what we've done here is to walk you through the steps, visually, for how to set up your Blogger blog's custom domain with Namecheap after you've purchased your domain.