I always hear that I should cook pasta in "salted water", but it never specifically says how much salt I should add to a specific amount of water.
The water should taste like the sea.
Use more than you think you should. I use a decent handful for a pound of pasta.
LL Stone and I cook pasta alike: it should taste like the ocean. Please promise us you won't use Morton's table salt. Use sea or kosher salt. Start with a palmful, about a tablespoon, added after the water comes to a boil, obviously so it'll dissolve. Taste it. Add more as needed. You'll be glad you did.
Use kosher salt, and add two tablespoons of salt for every 1 gallon/4 litres of water. The water will definitely taste like the sea, which is exactly the way you want it.
See the link for an outstanding video on boiling water, and many of the other videos are inspiring (How to Stride Ahead #2). And, kosher salt is better than table salt.