Jpratt2,
Your fears are well founded. You do not want the coach parked over open soil. Moisture will come up from the ground and condense on any metal that will be hurt by corrosion. It is best to put down a layer or more of heavy poly film - coach wide and long and then some planks for the tires so they don't punch through that film.
Even if you lay a gravel pad, putting film under it might be a good idea. Ask local people about that. I know in really wet areas, you need to make it drain.
This last coach came in on a hook, so we had to jack it up to get the planks and plastic under it. It sure is easier if you can lay things out and drive it onto the pad.
As far as how to take care of it? Remember that nothing good happens to an idling engine. Thermal cycles also aren't real good, so if you don't have to start it, leave it alone.
Matt