After opening the Administrative Tools/DNS snap in. Right click the Forward Lookup zones folder and choose new zone.

 

Select primary zone and ensure the store zone in active directory option is checked.

 

on the next screen choose an option for domain propagation.

 

Enter your domain name and click next to continue.

 

Ensure the allow on secure updates option is checked. Click next then finish.

 

 

 Repeat this process for each domain you wish to use with MintDNS. Unless of course you already have the zones setup etc.