First, pull out the racks and drip pans. Then scrub off debris and wash them in hot soapy water or soak them in a mild ammonia and water solution if they are really bad. Wipe down the inside surfaces with hot soapy water. Scrub off bits of burned-on gunk (You can use a commercial cleaner and follow instructions!). To prevent a buildup when something spills over while baking, pour table salt on it and when the oven is cool you will have a much quicker clean up.
Crammed Under-Sink Cabinet»