I would also recommend you pick up a copy of "Getting to Yes" if you aren't familiar with it. It is a quick read and research-based. A meatier book is "The Mind and Heart of the Negotiator". http://www.amazon.com/Mind-Heart-Negotiator-Leigh-Thompson/d... But it might be a bit late for that. (EDIT: Both were required texts in a class I had on "Negotiation and Conflict Management".)
Good luck.
Getting to Yes and Mind and Heart were the two required texts for a class I had on negotiation. Both are excellent books.
I highly recommend the second book especially. Towards the end of class, there is a group negotiation exercise. I thought it was quite good.