HERE ARE SOME TIPS AND TRICKS!
The 80/20 Rule: You will want to cook the pasta 80% of the way in the water and then finish the 20% in the sauce before service.
I recommend you cook your pasta al dente - it doesn't mean undercooked. The goal here is to have as much texture as possible without having it stick to your teeth.
While this might sound overly obvious, make sure you have enough water in the pot! If the pasta is too crowded in the pot, they'll stick to each other and won't cook evenly. 4 quarts of water in a 6-quart pot is a perfect starting point.
Bring the water to a boil. Toss in some kosher salt - don't be afraid to over-salt! If the water isn't boiling, the salt won't dissolve well, and you won't taste it properly. It should taste slightly less salty than seawater. A tablespoon or two should be sufficient. It all depends on your palette.
Drop the pasta in the boiling salty water slowly to avoid splashing boiling water on yourself. Keep the pasta moving - stir the pasta, so it doesn't stick together or to the bottom of the pot.
SPECIFIC PASTA INSTRUCTIONS:
Lumache: Cook lumache in heavily-salted water for 3-4 minutes
Mafaldine: Cook mafaldine in salted water for 3-4 minutes
Paccheri: Cook paccheri in salted water for 3-4 minutes
Bucatini: Cook bucatini in salted water for 2-3 minutes
Radiatori: Cook radiator in salted water for 2-3 minutes
Stuffed Pasta: Cook in heavily salted water for 3-4 minutes
*Pasta is stored in cardboard boxes which absorb moisture so cooking time may vary*