Vampires are made by draining a human of almost all of their blood and then feeding them the vampire blood. The new vampire experiences human death--it is painful and takes a considerable amount of time. When they awake a vampire, the change in their being is almost immediate. They are stronger physically, their vision is heightened, and, like any newborn, they have an immeasurable craving for nourishment...
I Grow Up:
Vampires feed exclusively on the blood of the living. They need the blood like humans need food, however, they will not necessarily die if they don't have it. Fledglings crave it as a human craves food. However, the older vampires get, the less they actually need it or even crave it. Lestat himself, as a very powerful vampire, admits that he takes blood because he likes it and not because he needs it.
The draining of blood is however the greatest pleasure vampires can experience, similar to the human orgasm. Vampires do not engage in sexual acts because the act of taking human blood is an ecstasy which overpowers any pleasure they might endure during sex.
As vampires age they become even more physically and mentally powerful. Most vampires can read the minds of humans and of other vampires. Some can jump very high, other vampires--usually older ones--can fly for long distances. The ancients--or those with older blood in them, such as Lestat--can create fire or even kill other vampires on sight.
Throughout their lives, vampires must hide during the daylight hours by sleeping in a coffin or underground, away from direct sunlight. Some sleep for years or even centuries if they find themselves bewildered by the passing of time, or if they are somehow seriously injured and need time to heal.
Vampires can be killed by the light of the sun, by fire, or possibly by beheading. The older they get, the harder they become to kill. Some older vampires (or strong younger ones like Lestat or Armand) can go into the sun without dying, however they are burnt to the point of near death. Beheading would probably do the trick, however, trying to accomplish it would get you killed pretty quickly. Drinking the blood of the dead is also harmful to vampires; however, they will not die from it, rather they would become extremely ill. Neither garlic nor crucifixes affect vampires negatively. Stakes do not kill them and they do cast a reflection in a mirror.