How Does This Differ from Windows 2000?
Many books have already been written on Windows 2000 and many more on Active Directory and Windows 2000 domains. If you plan to design a network using only Windows 2000, I suggest you pick up one of those other titles or get a subscription to Microsoft TechNet.
If you just want to add one or two Windows 2000 servers to a Windows NT network, they can be added just as any other Windows NT server would be. However, if you want to upgrade your PDC to Windows 2000, you must run your domain in "mixed mode." Your network will need to continue running in mixed mode until all of the domain controllers have been upgraded.