Get the most powerful SQL Server version ever: Microsoft SQL Server 2008 R2. New Datacenter and Parallel Data Warehouse editions provide premium, low-cost performance and scalability. In addition, Master Data Services, StreamInsight complex event processing, self-service business intelligence (BI), and database engine enhancements improve user value across the enterprise.
A 500-pages guide Upgrade Technical Reference for R2 is live in upgrade site (linked below).
For more information about SQL Server upgrade, please visit here.
Download: Upgrade Technical Reference for R2