My water is boiling too fast
Turn the temperature down - Once the pot reaches boil, it takes a lot less energy to keep it boiling, turning the temperature down it will keep it from boiling quite so violently.

Don't overfill your pot - Makes sure you are using a pot large enough to handle all the water and pasta

A teaspoon of oil will also help - This helps keep the water from building the bubbles causing it to foam over.  When you cook spaghetti, do you add olive oil to the boiling water?