As far as I can see... 19 reptile care specific books. A lot of them are on species I own (bearded dragon, leopard gecko, russian tortoise, ball python...no books on uromastyx?). I noticed for many species related books, I have two different books on the same species. I have two different kingsnake books, two different iguana books (never plan on getting one, but I used to love them when I was little), two bearded dragon books, and two ball python books. I also noticed that the books that aren't related to species I keep are usually books on species that I wish I could keep, but most likely never will (burmese pythons, iguanas, etc.).
Pretty good start to a reptile book collection for a 17 year old.