Beginner Body work

RP, just take one area at a time. You said the worst area was around the rear window. Go check it out thorougly and see just how extensive and how far the damaged area goes. Is rust under the rear glass, how far does it extend side to side, etc.. For that piece I'd check a junker someplace that I could cut that section off and weld it into my car. If you don't have a welder or cannot weld, pop rivet it in place and then have someone complete it by welding. Get that area looking good, prime it, and move on to the next area. There are several companies selling patch panels for your car. Auto Body Specialties, Sherman & Associates, Laysons, just to name a few. As far as paint removal, there are several methods to choose from. You can have car media blasted, you can use a chemical remover, or you can use a disc type or DA sander. I beleive the main thing you want to do is, prepare one area at a time if you are doing yourself, until the time comes to get paint done.