Negotiating is an art, and so depends a lot on context and mindset. Still these are patterns that many feel are tried and true:
You could also read GettingToYes. Arguably the best book on negotiation ever. -- JohnBrewer
"Arguably"? :-)
You should also take a look at StartWithNo by Jim Camp. It is my opinion that Start With No is better. -- StephanBranczyk
Fundamentals of Negotiation is an excellent quick summary of the area, and good to scan before setting out.
http://www.anu.edu.au/people/Roger.Clarke/SOS/FundasNeg.html
If you're negotiating about your salary, how do you know if you're being underpaid relative to the market? See SalarySurvey.
If you never had to break a negotiation because you refused an offer, it means that on average you're being underpaid. Many employers make hundreds of low-ball offers for a position, just to see if someone is desperate enough not to refuse their offers.
Many employers make hundreds of low-ball offers for a position They do? I've never worked for one. The saving would be outweighed by having to do hundreds more interviews.
A negotiating pattern that I have been a part of is, masses of people involved in the process, helps you win. Is there writing on this one? -- MarkDilley
Because it had little to do with negotiating and much more to do with employment, I moved ThinkTwoJobsAhead to CategoryEmployment.