Best practice is to backup your Active Directory daily, and if not possible, at least weakly (8 days).
More about backup and restoring AD please follow this link (http://technet.microsoft.com/en-us/library/cc771290.aspx).
This Micro Tutorial hows how you can integrate Mac OSX to a Windows Active Directory Domain. Apple has made it easy to allow users to bind their macs to a windows domain with relative ease.
The following video show how to bind OSX Mavericks to …