Recipe(tried): Nana's Calamari Sauce over Linguine

Doreen, this is something my grandmother traditionally made for our family every year on Christmas Eve. We all like it so much though, that she'd make it whenever we asked.

NANA'S CALAMARI IN TOMATO SAUCE OVER LINGUINE
2 pounds fresh squid - try to buy it pre-cleaned
1 recipe for marinara sauce (if using jarred, no sugar added)
1 pound cooked thin linguine a.k.a.lingue di passero (sparrow's tongues)

Cleaning Fresh Squid:
Rinse the squid in cold water.
Hold the head, grasp the squid by its tentacles and gently but firmly, pull out the entrails from the body sac. Discard the head and entrails.
Cut off the tentacles just below the eyes, being careful not to include the beak and set aside. Don't throw the tentacles away, they are edible and taste the same as the rest of the squid. Remove the beak and discard it.
Remove the cartilage which runs the length of the body sac, peel off the skin and discard both.

Cooking Squid:
Rinse the squid's tentacles and body sacs well under cold running water.
Cut the bodies into rings about 1/2" wide. If the tentacle "bunches" are small, leave them whole. If they're very large, cut them in half.
Bring the tomato sauce to a simmer and place the raw, cleaned squid in the hot sauce to cook for about 30 minutes or more. When cooked, they will be creamy white and firm.
In the meantime, cook the linguine until al dente, drain and return to pot.
Toss with some of the sauce to prevent sticking.
To serve, fill warmed bowls with cooked pasta and top with a ladle of the sauce and cooked squid.