The book is written mainly in a language called "Nadsat" ("teen" in Russian) which comprises of people, mainly teenagers using Russian words in otherwise English sentances. Most of the copies of the book come with a glossary in the back, however, you can usually understand what a word means by the context it is used in.
A Clockwork Orange is a very graphic and violent book, but it does teach the reader very important lessons about themselves and about life.
Stanly Kubrick made A Clockwork Orange into a movie that was released in 1971 and was promptly banned in several countries as it was viewed as too violent. There's a scene in the movie that was cut out because it was too violent and also a chapter in the book that was cut out for the same reason. However, now you can get copies of the orginal book and I have heard rumors that you can download the original movie version.