I think GoDaddy has a feature where they will redirect the domain you buy from them to your home machines address... but what they can't do is actually change the DNS record to go to your computer... unless you have a nameserver setup which I dont think you do.
So basically, if you want them to chnage the DNS records to go to your machine, you will need a nameserver, something I've never done but plan to.
But if you just want them to redirect the domain they will do this for a small charge (at least they did when I used godaddy). Its hidden somewhere in your domain options after you purchase it.