BP,
Collect the manufacturer and model number of everything you want then do a web search. All of those things were supplied by manufactures and much of the documentation is available for download. All you have to do is find it.
To check for propane leaks, start with the whole system. Use some clear tubing, rubber bands and a stick rule to make a manometer. Put that on the jet of one stove burner and turn the gas on and then off. The columns should separate by 11". Leave it alone. If they stay separated, you don't have a leak. (Except maybe at that burner - this did happen to me once in 50 years.) If you lose pressure, first look for something that isn't shut off correctly, the look for leaks in the system.
Matt