If not, I should have. They were far and away the most popular books in my elementary school's library. Lotsa cool pictures, straightforward rundowns of each monster, even more cool pictures. I remember the first six-volume series -- Frankenstein, Dracula, the Mummy, Godzilla, King Kong and Wolf Man -- a smattering of series two -- Mad Scientists and Creature from the Black Lagoon -- but holy fucking shit, there was a third series that had a Phantom of the Opera volume??? I can only imagine how awesome to 8-year-old eyeballs the vision of Lon Chaney on orange and B&W cover must have looked.
[I'd like to think that the ALFRED HITCHCOCK AND THE THREE DETECTIVES were second-most popular rentals, but, considering I haven't read one of the novelettes in 20-odd years, maybe I shouldn't.]