This is young-adult fiction and is one of the most frequently challenged books of 2004. It was challenged "for homosexuality, sexual content and offensive language."
The cover describes it as "Catcher in the Rye" meets "A Separate Peace."
The book is about a straight teen, Charlie, trying to find his way during his first year of high school. Charlie is a wallflower but he's trying to participate more and cope with the usual problems that teens face.
Some of Charlie's descriptions will make you happy. For example, he describes the first time as a baby he started laughing while his mother and aunt watched. The thought of a baby laughing is perhaps one of the more pleasant things in life and Charlie brings many such joyful moments to the reader's attention.
Charlie does have problems and he makes mistakes such as during a game of truth or dare, he is told to kiss the most beautiful girl in the room and he doesn't pick his girlfriend!
As far as the book being challenged, the issues given for the book being challenged do exist in the book and actually add to the book's quality. However, the main character only observes these things (wallflower remember?) and may not even be the real reason the book is challenged. You'll need to read the book to see what I mean.
I read "The Perks of Being a Wallflower" because someone at DU posted this link to the list of 2004's most challenged books in honor of Banned Book Week:
http://www.ala.org/ala/oif/bannedbooksweek/challengedbanned/challengedbanned.htm#mfcbhttp://www.ala.org/ala/oif/bannedbooksweek/challengedbanned/challengedbanned.htm#mfcb