What type of faucet are you trying to hook up to? A sink type faucet or a hose faucet? I do not know what Russ supplies with his units if anything to hook up to a supply line or faucet. If you are trying to hook up to a sink faucet you would need some adapters. Same goes for connecting to a hose faucet, you need an adapter. The adapters for a hose faucet I believe are available from Home Depot, Lowes or a hardware store. I don't know if they would have adapters for connecting to a sink faucet.
As for the valve on top of the unit, that sounds like the bypass/flush valve for flushing your RO membrane. If you have specific questions you can always e-mail Russ at Buckeye and he will get back to you quickly with answers to your questions.