What’s new in Windows Server 2012 ? : http://technet.microsoft.com/library/hh831769.aspx

also the main Technet home page: http://technet.microsoft.com/en-US/

Install, deploy, migrate to Windows 2012 RC DataCenter: http://technet.microsoft.com/library/hh831620.aspx

Download Windows server 2012 RC: http://technet.microsoft.com/en-us/evalcenter/hh670538.aspx