You fly at quarter speed and can glide over terrain and other obstacles at normal speed. However, you cannot move more than a couple feet above the ground. You fall at the rate of 30 feet per round (30 feet per 5 seconds).
At the start of each of your turns, you heal and regain that many HP. This does not consume your hit die. If you were dead due to HP loss, this brings you back to life. If you take fire damage, this effect doesn't apply on your next turn. You only die due to HP loss if you start your turn without successfully regenerating HP.