Guidelines for Negotiation assignment

I have a great discomfort with competitive, traditional bargaining. I'm always afraid I'll offend people, I don't like conflict, and I don't really know what I'm doing. As a result, I try to avoid these negotiations as much as I can, keep them as short as possible when I'm forced into them, and often feel like I've lost at the end of the day.

Now I've come to you for some advice on what to do. I have to do some major roof work on my house, and I'm about to negotiate with a contractor whose initial bid was $10,000 for the job. I've been taken to the cleaners by contractors in the past, so I want to negotiate well, but I also don't want to lose or offend this contractor. He was the only one I really liked of the three we interviewed, and the only one who gave us a firm price.

What advice do you have for me as I enter into these negotiations in a couple of weeks?

Assignment:

Give five ideas as short bulleted paragraphson what I should do to become more comfortable and effective in this negotiation.