If you've seen the TV-series you'll find the book very familiar, to the extent that you'll recognize the dialogue. 
 If you haven't seen it on TV, then you're in for an enjoyable read. 
 The story is a pretty standard detective story, with a twist that makes all the difference. 
 The main character, Dexter, works as a blood spatter analyst for the Miami police force, but he's also a sociopath and serial killer. 
 It doesn't sound like it would be funny, but the whole story oozes a dark murky sort of humor that is both situational, where the sociopath plays the role of a 'normal' human as well as the dialogue, which is occasionally funny and occasionally witty.