Strange Orange Mushroom
This looks like a type of wood decay fungi on the oak. It is a decay organism living off dead wood.
There is no easy way to determine which mushrooms are edible. We do not have a mycologist on staff and we are not authorized to identify mushrooms as to whether they are edible or not. We suggest that you contact the Mycological Society of Washington D.C.
You are wise to be cautious. Some mushrooms could make you very sick or kill you if you make a mistake.