Start with a stock pot of water, boiling to cook your Lasagna Sheets. While that is boiling, in a medium sauce pan fry up the Pepperoni. Once they are crispy, let them drain on a paper towel. In a 10 inch by 14 inch by 3 inch deep baking pan, pour 1 up of the Spaghetti Sauce to cover the bottom. Layer the Lasagna Sheets, than 1/3 of the Ricotta Cheese, Mozzarella Cheese, and than Parmesan Cheese. Put a layer of Pepperoni over those, and than repeat. After the last layer, top with the remaining Cheeses. Bake for approximately 45 minutes.