Algunos libros gratuitos de Microsoft
Buena colección de libros que Microsoft Press ofrece de forma gratuita en formato PDF, epub y mobi.
No son muchos pero tienen muy buena pinta (sobre todo si estás interesado en System Center, hay varios de ellos).

Introducing Microsoft System Center 2012 R2
Mitch Tulloch with Symon Perriman and the System Center team
January 2014
180 pages
Get a high-level overview of System Center 2012 R2—and get a running start transforming your datacenter and cloud-optimizing your business. This guide introduces core features and functionality, with technical advice and under-the-hood insights from a Microsoft MVP and members of the System Center team at Microsoft.
Download the PDF (12.4 MB)
Download the EPUB file (24.3 MB)
Download the Mobi for Kindle file (43.1 MB)