Thanks. Those things help.
If you are going to go I have found The Unofficial Guide to Walt Disney World by Bob Sehlinger to be worth its weight in gold. Amazon has it for $12.59 or pick it up at your library.
The BESTEST, CHEAPEST raincoat is a black garbage bag. Easily folded up for carrying in a back pocket. Make head and arm holes, use as needed, then throw away. Gets strange looks from some people, and envious looks from those that paid $6-$8 for a poncho.
The other posts suggesting off-site rooms are good ones. Get a cheap room with a fridge (you're not vacationing in the room - you're only showering and sleeping there). Something that helps is starting your day in the park when it opens (parking usually opens an hour before the park), then around lunch time go back to your room, eat, and TAKE A NAP. Then you'll be able to go back to the park and last until the fireworks show at closing time.