Beatty seems like a very dull character in the beginning. Once Montag talks about books, we find out that Beatty has actually read books himself before and is probably very intelligent.
From pages 76-80 Faber is described as a frail man. Although it doesn't say that he has books laying around like this but I feel that he may be hiding some because he used to be a professor. He is facing away from them because it's simply not allowed no matter how much he loves it which is implied between pgs. 76-80 when he reads the Bible.
Granger is a very mysterious character. Even though we know he is very passionate about books, it almost seems odd that he is out in the wilderness but also on the run. He mentions that he can memorize books from ages ago, which sounds strange, but Montag seems to trust him because of that shared passion so maybe he does have good intentions.