The starting point for finding information about all things IDA on Microsoft platforms is http://www.microsoft.com/ida/. Although this link currently redirects you tohttp://www.microsoft.com/windowsserver2003/technologies/idm/default.mspx, I have a feeling this will change as Windows Server 2008 approaches RTM.
The Windows Server 2008 main site on Microsoft.com also has a general overview called “Identity and Access in Windows Server Longhorn” that you can read athttp://www.microsoft.com/windowsserver/longhorn/ida-mw.mspx. By the time you read it, there probably will be more details on the site than there are at the time of writing this.
You can also find a developer-side overview of the directory, identity, and access services included in Windows platforms (including Windows Server 2008) on MSDN at http://msdn2.microsoft.com/en-us/library/aa139675.aspx.
If you have access to the Windows Server 2008 beta program on Microsoft Connect(http://connect.microsoft.com), you can get a lot of detailed information about AD DS, AD CS, AD FS, and so on. First, you’ll find the following Step-By-Step guides (and probably others will be there by the time you read this):
Installing, Configuring, and Troubleshooting OCSP
Auditing Active Directory Domain Services Changes
Active Directory Domain Services Backup and Recovery
Planning, Deploying, and Using a Read-Only Domain Controller
Restartable Active Directory
Certificate Settings
Active Directory Rights Management Services
Identity Federation with Active Directory Rights Management Services
Active Directory Domain Services Installation and Removal
Active Directory Federation Services
Be sure also to turn to Chapter 14, “Additional Resources,” for more sources of information concerning the Windows server core installation option, and also for links to webcasts, whitepapers, blogs, newsgroups, and other sources of information about all aspects of Windows Server 2008.