Adding salt to your pasta cooking water seasons the pasta from the inside out, but you can skip the oil. It will only coat the pasta when you drain it, and that prevents the sauce from adhering.
The best way to keep pasta from sticking is to use a large amount of water. Use 4 quarts of water to 1 pound of pasta. This means you should be cooking pasta in a 6- or 8-quart stockpot or Dutch oven. Stirring the pasta for a minute or two after you add it to the boiling water will also help keep it from sticking.