Try looking in the Kissimmee area. There are a bunch of cheap hotels there, but lower class. If you want everything really easy to get to, get a disney resort or something around lake buena vista, or something on 192. Avoid I-Drive, Airport, and downtown Orlando like the plague. I-Drive has nice hotels for conventions and walking, but traffic is a real PITA. The place is a damn tourist trap, only places good there are some restaurants. Airport is easily accessable, but probably won't be cheap, and going to Disney will take a good 45 minutes or more during the best of conditions, and ya gotta pay tolls back and forth. Downtown has ass, there aren't really any hotels, plus it takes at least an hour or more to get to Disney, even if you stay on expressways.
Driving isn't frustrating if you're just going into Disney and back. But beware, Orlando has it's fair share of traffic, urban sprawl with old roads, road rage, and worst of all, stupid friggin foreign (and some domestic) tourists who can't drive.