Here are some simple steps to help you cook perfect pasta.
For each pound of pasta, you need at least four quarts of water. Use a six-quart (or larger) pot so you have plenty of room for both and don't have to worry about the water boiling over. Add at least two tablespoons of coarse salt after the water comes to a boil.
Enough water and frequent stirring are the keys to keeping pasta from sticking. You do not need to add oil to the water (this actually prevents sauces from clinging to the pasta). After adding the pasta, keep the heat on high so the water returns to a boil as quickly as possible. Always cook uncovered.
When It's Done
Pasta should be al dente (firm to the bite). If undercooked, it will have a chalky core and floury taste; if overcooked, it will be limp and soggy. Start tasting the pasta two or three minutes before the end of the suggested cooking time; pasta will continue to cook a bit after it's drained.
Before draining the pasta, reserve one or two cups of the cooking water; the water contains starch from the pasta that will add body to sauces. After pouring the pasta into a colander, shake it a few times but don't rinse it (unless you are making pasta salad).
Immediately toss the pasta with the sauce of your choice, adding some reserved pasta water as needed to enhance the consistency of your dish.