A Clockwork Orange...What's the meaning?

Okay, I recently watched Stanley Kubrick's "A Clockwork Orange" and I would really like to know if there are any specific meanings to the movie. My sister said she likes it because it has an outspoken meaning to life. I don't quite get the meaning, even though I'm young still, I get most of the movie, is there any specific meaning to the movie? And if not, I would also like to read the book, know the name by any chance?