First and fore most "The Complete Chondro" by Greg Maxwell. Doesn't matter if you have one corn or a hundred Green Trees it is a must read for anyone in this hobby.
Next anything from the Manual series. Ball Python Manual, Boa Constrictor Manual etc. I have 4 of them and they are all great and up to date. Finally it's getting old but it's still worth having "The Complete Reproductive Husbandry or Pythons and Boas".
Hope this helps,