Microsoft has released a free e-book on SQL Server 2012. This e-book is for both IT Professionals and Developers and provides overview of what is SQL Server 2012. It covers topics like – different editions of SQL Server 2012, engine enhancements, disaster-recovery enhancements,performance and scalability, security enhancements, programmability and beyond-relational enhancements, various services in business intelligence development point-of-view etc.
You can download the PDF version free e-book from here.
For more details, refer the blog post in Microsoft Press Blog