NT4 Server & Win 2000 Server Coexistence

What is the best way to migrate an existing NT4 network to Win 2000? We currently have:

NT Server 4.0 sp6
NT Workstations sp6
Win 95/98 clients

We added a Win 2000 server and would like to gradually move to the 2000 platform. The workstations and 95/98 clients will remain the same.