PDI is a multiplatform tool, meaning that you will be able to install the tool no matter what your operating system is. The only prerequisite to work with PDI is to have JVM 1.5 or a higher version installed. It is also useful to have Excel or Calc, a nice text editor, and access to a database engine of your preference.
Having an Internet connection while reading is extremely useful as well. Several links are provided throughout the book that complement what is explained. Besides, there is the PDI forum where you may search or post doubts if you are stuck with something.