Peel and slice your eggplant into about 1/2 inch slices. Cover a flat surface (counter top, baking sheet, cooling rack, etc.) with paper towels or a kitchen towel and spread the eggplant slices on the towel in a single layer. Sprinkle each slice with salt and let rest for 30 minutes. This will remove some of the liquid from the eggplant.
When the 30 minutes is almost over, preheat the oven to 350 degrees. Heat 3 tablespoons olive oil in a large pan over medium heat.
After the 30 minutes have passed, use paper towels or a kitchen towel to blot the eggplant and remove the water that has gathered on the tops of the slices.
Add the flour to a bowl and dredge each slice of eggplant through the flour. Coat the eggplant on all sides and shake off any extra flour that doesn't stick.
As the slices are coated with flour, add them to the pan of hot oil. Cook for about 3 minutes per side, then remove the slices to a paper towel-covered plate to cool slightly. This will need to be done in batches; continue until all the eggplant has been coated in flour and pan fried, adding more oil to the pan as needed.
Coat the bottom of a 9x13 or similar sized baking dish with a thin layer of tomato sauce.
Top the layer of sauce with a single layer of eggplant slices (picture 1 below). Sprinkle each slice with mozzarella cheese (picture 2 below), then use the back of a spoon to spread a layer of tomato sauce on top of each eggplant slice (picture 3 below).
Repeat step 7 until all the eggplant slices are used, covering each layer with cheese and sauce. I usually get 2 layers. Cover the last layer with all the remaining sauce, 1/2 cup reserved mozzarella cheese, 1/2 cup Parmesan cheese and 1 teaspoon Italian seasoning (picture 4 above).
Bake the eggplant Parmesan uncovered at 350 degrees for 20 minutes, or until the cheese is melted and the tomato sauce is bubbly. While waiting, prepare the pasta according to package instructions.