The most critical point in your negotiation for a job will come before you ever focus on salary. Your guideposts are your goals. What are you looking for, in addition to salary? What is your alternative, such as staying in your current job?
What You Wish You Knew Earlier, Part 1: Getting to Yes
Some references are worth every minute of your time and more. Getting to Yes: Negotiating Agreement Without Giving In (3rd ed., 2011) by law professor Roger Fisher, anthropologist William Ury, and negotiation consultant Bruce Patton is a bookend reference in that category. This book provides a route to avoid the dead ends of winning everything or, worse, giving up.