A quality and slow burning carb like oatmeal is an excellent way to go. I prefer dry cereal and add lot's of fruit like blueberries (frozen). Quality fruit, particularly the dark purple ones and strawberries are not only quality carbs, but high in the antioxidants that are good for post-ride body repair.
Chris Carmichael's Food for Fitness is an excellent source of info on how to eat well for athletes.
Al