The Windows Server 2012 Core Network Guide provides instructions for planning and deploying the core components required for a fully functioning network and a new Active Directory domain in a new forest.
This guide explains how to build on the core network by providing instructions for deploying Group Policy Objects (GPOs) by using membership groups instead of the organizational units (OUs) that form the hierarchy of an Active Directory domain.
Check it out at
http://technet.microsoft.com/en-us/library/jj899807.aspx