If you bought the domain through your blogger dashboard then it will generally instant connect for you, you can check in your settings location. If you didn't then go to your settings and depending on which company you got it from (I think it's godaddy or enom), it'll give specific instructions for how you can connect your domain to you site.
You can establish a moreskilled identity for your Blogger® blog by configuring it to pointto one of the domain names you registered through us. rather thancoming into your Blogger URL to look at your latest blog post, guests enter your domain name's URL. for instance, by mapping your coolexample.blogspot.com blog to your www.coolexample.com domain name,guests focus solely on your domain name. To point your Blogger blog to your domain name, you got wind of domain name mapping, which configures your blog settings and domain name. You update your settings in your Blogger account and our Domain Manager: Park the domain name you wish to use along with your Blogger account on our parked nameservers. Edit the www CNAME record for the domain name you wish to use along with your Blogger account. This update tells the online browser to open your Blogger blog when guests[COLOR=#000000] enter your domain name's URL [/COLOR][B]within the browser address bar. Forward your domain name to use www. This step ensures your Blogger blog displays for [B]guests[COLOR=#000000] who [/COLOR][B]head to[COLOR=#000000] your domain name with or [/COLOR][B]without[COLOR=#000000] the www prefix. [/COLOR][B]for instance[COLOR=#000000], it displays for [/COLOR][B]guests[COLOR=#000000] who entered [/COLOR][B]both[COLOR=#000000] www.coolexample.com and coolexample.com.[/COLOR] [COLOR=#000000]Configure your Blogger account to use your domain name.[/COLOR][/B][/B][/B][/B][/B][/B][/B]