I love herp books!
For an idea of what it was like to be a herper back in the day.....
"Snakes in fact and fiction" James Oliver
"Snakes: the keeper and the kept" Kauffeld
"Snakes and snake hunting" Kauffled
"Life love and reptiles" Minton
The bible of rattlesnake books!
For the croc fans!
"Handbook of Alligators and crocodiles" Grenard
And one other!
"Poisonous snakes of the world" various authors
Then there are the heaps of field guides out there!