http://www.amazon.com/exec/obidos/ASIN/0915166127/thepsychologyinf

Assertiveness, as taught by counselors and Psychologists, typically has nothing to do with getting your way.. or "winning." It is about clear expression of your feelings and wishes. The Alberti and Emmons book has been around in various editions for many years and is still the "gold standard" if you want to teach yourself.