Not only are the hosts interesting and engaging instructors, but they are also leaders in the technology. One of the hosts, Jeffrey Snover, is the inventor of PowerShell.
"Learn Windows PowerShell 3 in a Month of Lunches", unlike many other PowerShell learning resources, does not require any prior programming experience.
The book works through the material at a pace that won't overwhelm most readers. Lab exercises at the end of each chapter reinforce the preceding material.
"Windows PowerShell in Action" is a comprehensive resource on PowerShell that covers everything from the history of PowerShell to error handling and security.
Where as some resources act as an introduction to both scripting and PowerShell, "Windows PowerShell in Action" requires that the reader already have a scripting or programming background.