Ro/di systems?

[Kar_Wash]

Looking to invest in a RO/DI system. Kent Marine Maxxima has caught my eye, but looking for suggestions.
Also how exactly am i suppose to use this device? It was mentioned briefly by a friend i should keep it in my garage with a 30 gallon trash can.
Do i need to hook the hose up to it , and how do i run the water, how often, etc?

Any info or suggestions would be much appreciated.