internal dns

I ran dcpromo to set up AD and during the install I had the wizard set up DNS for me. I want my DNS zones to be active directory integrated and I want my DNS servers to be root servers authoritative for the root domain at my site. I am using my ISP’s DNS as foworders to get to the internet. I have read that I must edit the cache.dns file to make my server a root. Can I just remove the root servers from the root hints tab and add my servers ip address or do I have to edit the cache.dns file? Also is this all I need to do to make my server a internal root server? Should I have set up DNS manualy instead of letting dcpromo do it for me?