Hi mopargilley and welcome
What year, model Georgetown do you have?
How many miles?
As you are finding out a true owners manual dosen't exist.
You just need to start gathering information here and individual equipment manuals as you go. We also have here basic wiring diagrams as well as troubleshooting of specific equipment.
Here are a few things you can do and check
Engine Oil level. condition
Check air filter if it needs to be replaced
Transmission fluid condition
Brake pads thickness and maybe a time to flush the brake system
Engine cooling system
Chassis battery check and clean, fill and really see if they will hold a charge or not
All appliances inside
Drinking water tank. Flush with a half a cup of bleach and make sure you circulate using the 12 volt pump. this will kill mold, slime and germs in the system
Clean out balck and grey water tanks by totally filling them to the top and dump them. This will remove any garbage that may have not been cleaned out prior.
Now if you have any specific quetions just go ahead and ask away.
We are here to help.