I believe that the character Charlie is the hero. I think that Charlie is the hero because through out the story he has been changing. For example, so far, Charlie went from being the kid who didn't have friends and stood against the wall at school dances, to the kid who does have friends, the kid who has friends that don't go to school dances, the friends that except him and think he is pretty great. I think that Charlie's change is good for him, but not because he has reached a higher level on the popularity scale, but because he has people around him that appreciate him more than anyone else ever did.
I think that the character Patrick acts as a mentor through out the story. I think of Patrick as the mentor because he is always the one giving Charlie advice. He is also the one who always knows what is going on. For example, in the story he knows the gossip and he knows where the parties are and he knows how to handle things. Patrick is also the one who Charlie really looks up to. I think that Patrick is a really good mentor for Charlie because while he smokes and does drugs and drinks when he isn't supposed to, he really does lead Charlie in the right direction. Plus Charlie doesn't really have anyone else to look up to, his brother is kind of dull, and he is in college far away anyhow, and his father and him don't really have that great of a relationship, so Patrick is pretty great for him.
I think that the character Sam is almost like a shapeshifter. I think she is a shapeshifter, not because she is always changing sides, but because she represents uncertainty in Charlie's eyes. Charlie has a crush on her, but she says that she likes him a lot, but in a friend way. Meanwhile she goes ahead and kisses him. Charlie is uncertain whether he should think of her in "that way" or not. So it isn't like Sam in is an enemy to Charlie. She just in someone that he is unsure about. He doesn't know where they stand.