DNS Question – Important

I am preparing to upgrade my NT 4 servers to Windows 2K and Active Directory, but I have a question about DNS. Right now are DNS is hosted at our ISP, I realize that I need to have an Internal DNS server for Active Directory. My question is, can I just add the IP address of the new DNS server that 2K will install to the list of DNS servers on the workstations on the Lan, or should I just setup forwarding on the 2K DNS server and allow the name resolution to be handled that way, are there any other ways to set this up, what are the benefits of either way, any help would be great as I am planning to do this over the weekend.

Thanks In advance.