Yes one clove will become a bulb. Yes, plant in the fall, and yes more parts are edible. You can cut the greens when young and use as chives I have heard, also if you have a hard neck it will send up a flower stalk, cut that off as soon as you see them, they are very yummy with a mild garlic taste! Plus you don't want that left on your plant. Harvest when the leaves start to die.