Pour enough oil into a heavy large saucepan to reach the depth of 3 inches. Heat over medium heat to 350 degrees F. Mix the flour, parsley, salt, and pepper in a large bowl. Working in small batches, toss the squid into the flour mixture to coat. Carefully add the squid to the oil and fry until crisp and very pale golden, about 1 minute per batch. Using tongs or a slotted spoon, transfer the fried calamari to a paper-towel lined plate to drain.
Place the fried calamari and lemon wedges on a clean plate. Sprinkle with salt. Serve with the marinara sauce.
Simple Tomato Sauce:
In a large casserole pot, heat oil over medium high heat. Add onion and garlic and saute until soft and translucent, about 5 to 10 minutes. Add celery and carrots and season with salt and pepper. Saute until all the vegetables are soft, about 5 to 10 minutes. Add tomatoes and bay leaves and simmer uncovered on low heat for 1 hour or until thick. Remove bay leaves and check for seasoning. If sauce still tastes acidic, add unsalted butter, 1 tablespoon at a time to round out the flavors.
Add 1/2 the tomato sauce into the bowl of a food processor. Process until smooth. Continue with remaining tomato sauce.
If not using all the sauce, allow it to cool completely and pour 1 to 2 cup portions into freezer plastic bags. This will freeze up to 6 months.