Domain Design

In the situation you discribe I would choose for a Single Master Domain Model and place all users in one domain for easy administation. And create some resource domains with the correct trust relations between them. You have to be carefull though with a master domain with all users to place some BDC on strategic places to reduce the network load..

maybe you should take a look at

http://msdn.microsoft.com/library/winresource/dnwinnt/S86F9.HTM

http://www.microsoft.com/Exchange/en/55/help/documents/server/XCP06014.HTM

http://windows2000.about.com/compute/windows2000/library/weekly/aa062099.htm

We run such a single-master domain (decided upon before I could exercise influence) and indeed it's the best that can be achieved with 100% MS technology (while even ADS does not improve strongly for WAN's...)
However now that you also have some NetWare in place, why not go for NDS eDirectory which also runs under NT? It acts 100% like a NT domain towards all applications but is far, far better in replication over a WAN and in structuring your users and groups...

Hope this helps,

/ The Netherlands

Installing NDS for NT is a great idea, since Netware is still the champ (for the time being) of directory services, and having a single point of administration would be a big plus. However, if it is not possible to implement NDS for NT at this time,you would be best served to redesign your NT 4.0 model with Windows 2000 Active Directory in mind. That way if you choose to upgrade to Win2K, some of the required infrastructure will already be in place. There is a Microsoft White paper that discusses this at http://www.microsoft.com/ntserver/management/deployment/planguide/PlanForNT5.asp

I hope this helps, and good luck!