How can I plant an avocado seed to grow an avocado tree?

To plant an avocado seed, remove it from the fruit and wash off any remaining flesh. Insert toothpicks into the seed to suspend it over a glass of water, with the bottom half submerged. Place the glass in a warm, sunny spot and change the water regularly. Once roots and a stem appear, transplant the seed into a pot with well-draining soil, leaving the top half exposed. Water regularly and provide sunlight to help it grow into an avocado tree.