I am an avid Objectivism fan and I have read just about all of her works, and I consider her the greatest philosopher of all time. Anthem is one of her earliest books and is the easiest read book that she has ever written.
Anthem tells the story of what the world would be like if the collectivists’ principles were to be followed and not compromised. The author describes a horrible world where all self-esteem, pride of ones own work, individual freedom and the right to choose what one wants to do with ones own life have been completely destroyed.
Anthem is an excellent book to get to know the writings of Ayn Rand. I always recommend Anthem as the first book to read if you have never heard of the author before. It is easy to read, and it gives you a good understanding of what is to come in future readings of Ayn Rand. Even though the tone is negative in the entire book, you will realize the principles behind the evil in the world, and by the end of the book you will be touched and you will feel your own individualism screaming to get out of your body.
After you have read Anthem, go ahead and read other books by the same author, like Atlas Shrugged, The Fountainhead and The Virtue of Selfishness.