Well, you'll really need to be specific about what types of animals you want to keep. I've never found general information in a book that I couldn't find on the internet, but I have found that books that go in depth on a particular group of animals are often good.
I've mostly concentrated on Rhacodactylus sp. so far (crested geckos and giant geckos) and the guide book Rhacodactylus: The Complete Guide to their Selection and Care, by Allen Repashy, Phillipe De Vosjoli and Frank Fast is wonderful. I call it my gecko-bible.
I've just ordered Chamaeleo Calyptratus by Wolfgang Schmidt, so I'll offer a review of that in a while, but I've heard it recommended often. My advice on finding a book is to first do exactly what you're doing, find out what other people like. Then look for a book that provides data on the climate and ecology that the critters live in in the wild as well as information on husbandry.