Rod,
You have a great deal of good advise here and I don't disagree with any of it, but I would like to add some suggestions based on my experience.
First, comb the web for an owners group. I am sure there is one. Look at irv2.com, yahoo.com, rvillage.com just for starters. Manuals for all the internal stuff can probably be downloaded. Get them and read.
Next is directly related to the "Truck" half. Get the chassis manuals. Even if you don't plan to work on, if you have them and have trouble someone with a wrench might be able to make things better.
Few people keep a vehicle 20+ years. When you do there is a chance to learn some serious lessons that I will pass along.
First - When it comes to maintenance, if you didn't do or can't prove it was done count on it was not....
Second - Everything that is not metal can age out. So, change all the fluids, brake should be first (it does collect water with age and starts to corrode expensive parts), coolant does not wear out but the corrosion inhibitors get used up. Of course you will service the engine trans and maybe the rear end. Inspect all the rubber parts - belts, coolant line and the brake lines. If it looks bad, replace before you go anywhere.
With some care, you should have many boring miles (sometimes excitement is not welcome) to wonderful places that you have only heard about.
Matt