The following books provide useful information and advise on workplace negotiations:
A Woman's Guide to Successful Negotiating: How to Convince, Collaborate, and Create Your Way to Agreement by Lee Miller and Jessica Miller
The Shadow Negotiation: How Women Can Master the Hidden Agendas that Determine Bargaining Success by Deborah Kolb, Judith Williams, and Carol Frohlinger
Get Paid What You're Worth: The Expert Negotiator's Guide to Salary and Compensation by Robin L. Pinkley and Gregory B. Northcraft
Are You Paid What You're Worth? The Complete Guide to Calculating and Negotiating the Salary, Benefits, Bonus and Raise You Deserve by Michael O'Malley
The Smart Women's Guide to Interviewing and Salary Negotiating by Julie Adair King
Although the following internet articles do not address negotiations in the context of sex discrimination, they do provide some useful tips on how to ask for better pay, promotions, and benefits.
Basic Negotiation Tips is among the many articles on workplace issues available at.
Careerjournal.com also has a collection of articles on negotiation around salaries and employee benefits.
Monster.com provides a quiz to test whether you are prepared to ask for a raise.
"How To Get A Better-Than-Average Raise" provides more information on how to prepare for salary negotiations.