Here's a great site: http://www.reexamine.org/quotes/ It uses their own literature to show what's wrong with them. It doesn't draw conclusions for you, it just quotes their stuff.
One big "stumbling block" for me was the treatment, or lack thereof, of pedophiles. They require two witnesses to even disfellowship a child molester.. how many abusers will abuse in front of a witness? Then, if they are convinced of a child molesters guilt they will take away their priveleges.. reprove them, etc. but they do not report them to the police, and they do not allow the congregation to be informed of the nature of the monster in their midst.
I know one woman, with children, who almost married a JW man who had a history of molesting children. A friend found out about his past and let her know. The elders in her hall knew of his past and that they were dating and that she had children, yet they chose not to tell her. Why? It would be considered slander. If it was discovered that her friend told her, the friend could be disfellowshiped for slander. I don't know about you, but to me this mess does not sound like it's under God's direction.
I hope some of this helps.
Misty