One of the most comprehensive and engaging books on social psychology is Zimbardo's relatively recent The Lucifer Effect. The first half of the book details the Stanford Prison Study as well as its connection to the events at Abu Ghraib. Even those who think they already know a lot about the prison study will learn something new. The second half of the book reviews most of the social psychological research conducted during the 20th century. It's a well-written counterpart to Elliot Aronson's equally entertaining and enlightening book The Social Animal.
For more information on the Stanford Prison Experiment, visit Zimbardo's website. You'll find links to even more resources on the topic.
Some do challenge Zimbardo's perspective, as in this Slate article from 2004, "Situationist Ethics: The Stanford Prison Experiment doesn't explain Abu Ghraib."
On another note, if you are not familiar with the true story of Kitty Genovese or the concept of the "bystander effect," you can find a full account of her murder at TruTV.