It would be good first to review the October/November 2011 Public edition of the Watchtower to understand the Society's arguments. Of course, I am finding that most Witnesses do not understand even how to do the 7 times calculation...or how to argue for many of the Society's interpretations on matters. For the most part, the "Slave" says it--end of story. Many are no better than some churchgoers I used to talk to at the door who used to tell me, "My preacher says it and that's good enough for me!"
Once you understand their arguments, then you can read the other side of the matter more effectively. Yes I know some of this might seem like dry history, but the importance of being able to comprehend this cannot be underestimated.
This is the thread that really helped me: http://www.jehovahs-witness.net/watchtower/bible/215282/1/WT-Nov-1-2011-public-When-Was-Ancient-Jerusalem-Destroyed-Part-2
Here is a thread of threads: http://www.jehovahs-witness.net/watchtower/bible/222960/1/e2809cWHEN-WAS-ANCIENT-JERUSALEM-DESTROYED-e2809d-Why-does-it-matter-The-Watchtower-October-1-2011-and-November-1-2011