If you want to point your DNS for a domain purchased from GoDaddy to Mod.Black here's what you do. (We'll also do it for you, for free, if you prefer. Just shoot an email to email@example.com or send us a live chat)
Login to your GoDaddy account, hover over your profile to reveal the Quick Links section.
Select "Manage Domains"
You'll see your domains, select the one you want to point to Mod.
Click on the domain and reveal the Domain Settings page:
Scroll down to the bottom to the Additional Settings section:
In the Additional Services section select "Manage DNS"
This will reveal the DNS management panel. You can edit the records to match these values:
You will generally have to create a new "TXT" record to add "v=spf1 include:_spf.mod.black ~all"
You can see the list of records here.