SQL Server 2012 AlwaysOn Failover Clustering

Now I start to install and experience SQL Server 2012 AlwaysOn Failover Clustering

http://www.contentinstaller.net/Install/Content/DEMO_SQL11UPD01-DEMO-04
https://social.technet.microsoft.com/wiki/contents/articles/10740.demo-transcript-configuring-sql-server-2012-alwayson-failover-clustering.aspx

I am using the following link to configure:

http://blogs.technet.com/b/canitpro/archive/2013/08/20/step-by-step-creating-a-sql-server-2012-alwayson-availability-group.aspx

First, it seems that I have to configure Active Directory for Windows Server 2008R2. And I need to know the benefit of SQL Server Failover Clusters:
http://www.brentozar.com/archive/2013/08/introduction-sql-server-failover-clusters-video/

Updating...

http://blogs.technet.com/b/scvmm/archive/2012/10/24/how-to-configure-sql-2012-alwayson-availability-groups-in-system-center-2012-virtual-machine-manager-service-pack-1.aspx
http://www.sqlpassion.at/archive/2012/03/21/sql-server-2012-alwayson-availability-groups-part-1/

http://msdn.microsoft.com/en-us/library/cc558976(v=bts.20).aspx