Here's some stuff from MS that should help you out:
 
Windows 2000 DNS and Active Directory Information and Technical Resources (298448)
http://support.microsoft.com/default.aspx?scid=kb;[LN];298448
 
How to Configure Active Directory on a Home Network (260362)
http://support.microsoft.com/default.aspx?scid=kb;[LN];260362
 
HOW TO: Create an Active Directory Server in Windows 2000 (300921)
http://support.microsoft.com/default.aspx?scid=kb;[LN];300921
 
Troubleshooting Common Active Directory Setup Issues in Windows 2000 (260371)
http://support.microsoft.com/default.aspx?scid=kb;[LN];260371
 
Setting Up the Domain Name System for Active Directory (237675)
http://support.microsoft.com/default.aspx?scid=kb;[LN];237675
 
Configuring Windows 2000 DNS to Support Active Directory
http://www.microsoft.com/windows2000/techinfo/reskit/deploymentscenarios/scenarios/dns_02_sir.asp
 
How to Verify an Active Directory Installation (298143)
http://support.microsoft.com/default.aspx?scid=kb;[LN];298143
 
Remember, DNS is the absolute backbone to getting this to work. Make sure you understand how DNS is to be setup *before* you start deploying AD.
 
Most of the stuff that applies to Windows 2000 Server will be the same for Windows Server 2003. However, Windows Server 2003 has more tools and utilities for working with AD, and that can be researched separately.