I’m a huge fan of “Getting to Yes” by Fisher, Ury, and Patton. An amazing book! Particularly if you believe, as I do, that cooperative organizations are the dominate lifeform of the internet.

The link above is a reasonably complete outline of their short book. An even shorter summary is:

• Seperate the people from the problem.
• Focus on interests, not on positions.
• Invent options for mutual gain.
• Use objective criteria

While those are very helpful rules to keep at hand. I’ve gotten as much and maybe more help from thier outline of how to handle various problems that arise as you negotiate.