If you want to approach it from a non-threatening, non-JW point of view, I would recommend Combatting Cult Mind Control by Steve Hassan.
Without attacking the JWs at all, he highlights similar tactics that most cult groups employ in one form or another. This is the kind of information that "clicked" with me when I was an active JW. I was watching a Social Psychology lecture on the university channel and the professor was describing group dynamics, how groups operate to control people within the group, and how groups operate to attract people to join the group and keep them from leaving the group. Without saying a word about JWs, I could identify a JW-example of the situations he described. It was a true moment.