Great book! If you can find it, read the 1st edition - it's slightly shorter, and the ending is different.The original ending fits the rest of the novel better than the revision.
As far as other commenters concerns go, I don't consider this an adolescent book at all, and the added sex descriptions in the revision are laughably mild in the 21st century. I'd also add that if you are going to review a book, it helps to read the entire book, rather than to skip to the ending and think you've read the book.
If this edition is all you can find, no matter, read away. It's an very entertaining novel.