First things first, you gotta check out this list!!...Eric ligman's list was so popular, he added a bunch more even!!...
Large collection of Free Microsoft eBooks for you, including: SharePoint, Visual Studio, Windows Phone, Windows 8, Office 365, Office 2010, SQL Server 2012, Azure, and more.
http://blogs.msdn.com/b/mssmallbiz/archive/2012/07/27/large-collection-of-free-microsoft-ebooks-for-you-including-sharepoint-visual-studio-windows-phone-windows-8-office-365-office-2010-sql-server-2012-azure-and-more.aspx