Houston traffic is horrendous! I've lived her 30+ years and know what to expect so it's not quite as bad, but drivers here are very aggressive and a lot of them are terrible.
You have drive very defensively and be ready for lots of delays. If you are coming from somewhere else, staying downtown is the way to go. There are shuttles to and from the airport and from the hotel to the convention center. Depending on which one you stay in, you can even walk.
And deb is right. Bring comfortable walking shoes and I'll add bring your camera and enjoy.
Edit: I should also add that you can get a catalog and get a lot of info by going to Quilts, Inc's website and clicking on Houston Festival. Quilts, Inc. is the company that puts on the Quilt Festival here and in a few other places.