Angelica I'm 14 and I just read it, it really depends on the maturity of the person. Lots of swears, but really not too graphic.
Sharon There was one section in the book where you read a short story written by the main character as an adult. In it, sexually graphic situations were described. In addition, the book contains a lot of "f" words and "f your mother (in this particular way)" type of talk. I wish there was less of that, because I think it would be a great book for middle or early high school students. With that said, I think a Junior or Senior in high school would be fine.
Eman Paelmo I think this is the first time I watched a movie and got out to find the book. Both are very good. And yes I read this when I was in high school, so it's good reading.