Hi Super Becka,
You might find "So Many Versions?" by Sakae Kubo & Walter Specht to be helpful in discussing the errors of the NWT. I don't know if it is still in print, but the book was published by Zondervan.
One interesting quote from page 103 of the book regarding the NWT:
"The jargon which they use is often scarcely English at all, and it reminds one of nothing so much as a schoolboy's first painful beginnings in translating Latin into English. The translation is marked by a wooden literalism which will only exasperate any intelligent reader--if such it finds--and instead of showing the reverence for the Bible which the translators profess, it is an insult to the Word of God."