Preheat the oven to 375 degrees F (190 degrees C). Rinse fish fillets with water, and pat dry with paper towels.
In a shallow bowl, mix together the cracker crumbs, garlic salt, pepper and seasoning salt. Set aside. Coat the fish fillets with flour, shaking off the excess, and place in a baking dish. Coat the tops of the fillets with salad dressing, then press on a layer of seasoned cracker crumbs. Flip over, and repeat on the other side.
Bake for 25 minutes in the preheated oven, until fish is white and flakes easily with a fork.