Muesli is a great one since it doesn't require cooking. Just soak the oatmeal the night before and then add yogurt, fresh or dried fruit, nuts, etc. in the morning. It's a great breakfast especially in the summer time/warmer months.
Oat bran is an alternative to instant oatmeal. It cooks exactly the same way, but I think it tastes much better (I'm not a fan of instant oatmeal).
I would make things and put them in the freezer: waffles, pancakes, muffins, etc. I've even made breakfast sausage before and frozen it after cooking. All it needs is warming up.
Baked eggs are delish. Just butter a oven-proof dish, put a little sour cream or yogurt in the bottom and crack an egg on top. Bake until done to your liking. If you have leftover cooked veggies, you can tuck some on the sour cream before you crack the egg on top, tomato and spinach are both good.
You can cook an egg in the microwave. If you crack the egg in a bowl about the size of an english muffin, the kids can make breakfast sandwiches with an egg and a slice of cheese. (Just read that you don't have a microwave, but maybe someone else could use that one.)