What you need for this book
The most friendly development platform for the readers of this book is Visual Studio 2015 because some material, as the book's title indicate, is specific to F# v4.0 or above versions. If you already have Visual Studio 2015 Professional or above editions you are ready to go without any extra effort.
Otherwise you may install free Visual Studio 2015 Community edition from https://www.visualstudio.com/vs/community/.
For other options available for Windows platform please visit fsharp.org at: http://fsharp.org/use/windows/.
Somewhat limited set of book's code samples will also work under Linux and Mac. For correspondent installations instructions please visit http://fsharp.org/use/linux/ and http://fsharp.org/use/mac/.
Requirements to the hardware are dictated by listed above versions of development environments.