The official SQL Server AlwaysOn team blog.
Writer:Cephas Lin (Microsoft)
Contributors: Sanjay Mishra (Microsoft)
Technical Reviewers: Aditya Samant (Microsoft), Juergen Thomas (Microsoft), Prem Mehra (Microsoft), Charles Mathews (Microsoft), Jimmy May (Microsoft), David P. Smith (ServiceU)
Content Program Manager: Glenn Minch (Microsoft)
Summary: This migration guide provides guidance for customers who have deployed database mirroring for local high availability and log shipping for disaster recovery based on SQL Server 2008 R2 or earlier and now want to upgrade to use SQL Server 2012 AlwaysOn Availability Groups. The migration sequence presented here is a best-practice approach that preserves the high availability and disaster recovery capabilities of your databases during most of the migration process.
This guide is Part I of a two-part series that describes planning considerations and deployment of a complete migration scenario. The information in this Migration Guide series can help you to successfully move to a high availability and disaster recovery (HADR) solution based on AlwaysOn Availability Groups.
Read on: http://msdn.microsoft.com/en-us/library/jj635217