Pneumatics is a system for putting pressurized air to practical use. Want to know more? This website better explains how you can use compressed air to transmit forces and store or carry energy to make pneumatics DO work, like crushing aluminum cans or adhering labels to a jar.
If you are interested in hydraulics, there is no better place to practice. The biggest difference between the two is the power source. Rather than air, hydraulics uses oil or hydraulic fluid.
Festo Didactic TP-101 CP Pneumatics Kit: Because this is proprietary equipment that is not widely used, little is available online. The best information about the kit can be found in the FESTO FluidSIM program on your desktop.
FESTO FluidSIM: find the program on your desktop.
Poke around the FluidSIM program to get started. Several experiments will start you on your way to using the equipment to DO more.
General ideas for getting the equipment to work can be found on the home page.