There have been tons of books written on negotiating, most of which contain more useful content than any advice thread or blog post. Given the huge difference negotiating makes, these books pay for themselves hundreds of times over.

I'm a big fan of anything written by Roger Dawson. Yes, it's written in sales-y self-help style, which you'll probably subconsciously resist, but the content is gold. Here's a link to his 'Secrets of Power Salary Negotiating':

http://www.barnesandnoble.com/w/secrets-of-power-salary-nego...