I really liked this book. I normally like books which I manage to read during 1 or 2 evenings. 
 People and reviewers compare this book to The Catcher in the Rye. It indeed resembles Salinger's masterpiece. The main character, Charlie, is a troubled teenager who has gone through a childhood trauma (which the reader finds out about only by the end of the book). Apart from having all usual teenage problems (girls, first sexual desires, fear about the future, etc), he's an extremely shy, sincere and naive kind of boy. 
 The story is told from Charlie's point of view in a form of letters he sends anonymously to somebody not mentioned in the book. Probably somebody chosen randomly. I really liked the fact that in the very beginning he acknowledges (after Bill, his English teacher, points it out) that his writing is rather muddled and confusing (and it really is so) and then he works on improving it, so by the end of the book it's really more coherent and logically structured, except for the times when Charlie writes while having some psychotic outbursts - that's when he can't control his writing and thinking at all. 
 I honestly don't understand people who hate this book. You can feel neutral about it (if you were a boring never-thinking-about-anything kind of teenager), but how can you hate it? 
 All characters are as believable as believable gets. All their inner struggles, behaviour, dialogues - everything is just pure life itself. 
 I like stories like this one. They are honest. And stories like this have endings when you don't really know what happens next and the author just tells you that life is what should happen next. And you, as the reader, can decide for yourself - what kind of life it will be.