Local
Windows 2000 Mixed: This is the default functional level
yes it is
User
Active Directory was previewed in 1999, released first with Windows 2000 Server edition, and revised to extend functionality and improve administration in Windows Server 2003. Additional improvements were made in Windows Server 2003 R2. Active Directory was refined further in Windows Server 2008 and Windows Server 2008 R2 and was renamed Active Directory Domain Services. Active Directory was called NTDS (NT Directory Service) in older Microsoft documents. This name can still be seen in some Active Directory binaries.
In Windows Server 2011 it is called Active Directory.
Default Domain Policy and Default Domain Controller Policy
Domain Controller
Active Directory Recycle Bin helps minimize directory service downtime by enhancing your ability to preserve and restore accidentally deleted Active Directory objects without restoring Active Directory data from backups.By default, Active Directory Recycle Bin in Windows Server 2008 R2 is disabled. To enable Active Directory Recycle Bin, your environment must meet the requirements to completed scenarioused to restore object deleted form AD or restore Multi OUs.
The default link name is Default first site
Active Directory
transitive with bridging enabled.
Some books one could use as tutorials for Active Directory are Active Directory Cookbook, Active Directory for Dummies as well as Windows 2000 Active Directory. All have various problem solving techniques one could use and they can be easily referenced.