We look for agreement between ourselves and others. You should strive for agreement, not victory. Nor should you passively accept whatever is initially offered.
Most employers regard a good negotiator as more valuable.
Review trade publications and other printed sources for salary studies. Ask your contacts about salary levels. Know what you want in terms of not only starting salary but also other elements of the total package. Establish an aspiration level, a target figure that you would like to achieve. If possible, find out what others are earning in positions comparable to the one you are discussing.