Windows PowerShell in Action, Third Edition by Bruce Payette, Richard Siddaway

In 2006, Windows PowerShell reinvented the way administrators and developers interact with Windows. Today, PowerShell is required knowledge for Windows admins and devs. This powerful, dynamic language provides command-line control of the Windows OS and most Windows servers, such as Exchange and SCCM. And because it's a first-class .NET language, you can build amazing shell scripts and tools without reaching for VB or C#.