I just watched read it and weep a few days ago and remembered, holy crap! There was a book about this movie that was a favorite of mine. Man this was my favorite book when I was in middle school. I loved the message of the story and the idea of a fourteen year old's diary becoming a bestseller.
This is a fun, quick, unique read. I'd recommend this to middle school girls, maybe even some high schoolers; but mostly this book is aimed towards younger readers. I'd also say watch the movie read it and weep. Its not as good as the book but really what movie is? ;D