For perfect pasta every time . . .
In a large pot (8-quart capacity is ideal), heat 4 to 6 quarts of water to a rapid, rolling boil for one pound of dry pasta. (You can adjust the amount of water depending on how much pasta you are cooking).
When the water reaches a rolling boil, add 1 tablespoon of salt for every pound of pasta, if salt is desired. Then add the pasta gradually, as you stir. Allow the water to return to a rapid boil.
Stir the pasta when it first goes into the water, when the water returns to a rapid boil, and occasionally during cooking to prevent it from sticking. Begin turning the pasta after the water returns to a rapid boil.
Because manufacturers have tested their brands and shapes for the best cooking times, follow package directions for length of time. Use a long-handled fork or spoon to taste for doneness. For pasta cooked "al dente," which means "to the tooth" in Italian, it should be slightly chewy with a very small white dot of uncooked core at the center. For more tender pasta, there should be no trace of white uncooked core.
Drain, but DO NOT rinse pasta unless it is to be used in a cold salad, reserving a small amount of the pasta cooking liquid. Toss the pasta immediately with sauce and, if the sauce is too thick, add some of the reserved cooking liquid a little at a time until the desired consistency is achieved.
If the pasta will be used in a cold salad, drain and rinse with COLD water, and immediately drain again. Then proceed to prepare your dish.
Source: National Pasta Association
(c) Copyright 1999. The Christian Science Publishing Society