Free eBooks (in multiple formats) from Microsoft Press about Windows 10, Windows 8.1, Windows 8, Windows 7, Office 2013, Office 365, SharePoint 2013, Dynamics CRM, PowerShell, Exchange Server, Lync 2013, System Center, Azure, Cloud, SQL Server, etc.
I got some of these last year, and they're a fantastic learning resource for anyone working in I.T.
