Exchange 2003

Ok, i setup Server 2003 and Exchange 2003. I have a domain on another dns through godaddy.com. The mx records point all mail to my ip address. To setup exchange i had to setup a dns server and active directory. I have those properly configured to setup users and internet access and such. The name of my active directory is trent.local. I havnt really setup my dns for my website due to not knowing how. What do i have to configure on my dns and in exchange 2003 to become my mail server for my domain. Any help is greatly appreciated.