Microsoft Press released a lots of free e-books including: SharePoint 2010/2013, Visual Studio light switch, Windows Phone, Windows 8, Office 365, Office 2010, SQL Server 2012, Azure, and more.
http://blogs.msdn.com/b/msgulfcommunity/archive/2012/08/28/large-collection-of-free-microsoft-ebooks.aspx
Rajesh Patel
R.P.A Developer | Developer Trainer | Clean Code Evangelist