This book could be called a grandmother of all the books on self-assertion that followed it. A nice and easy read that throws light on our own points of weakness, as well as those of others.
Basic Assertive rights:
1. The right to ask for what we want (realising that the other person has the right to say NO).
4. The right to make our own decisions and to cope with consequences.
12. The right to change ourselves.
Being assertive is about what is fair to all involved parties, and not just what is fair for us.
The book will help you understand that if you have not allowed yourself to express your opinions/desires/needs, that doesn't mean that people that do express them are in the wrong, but that you've been stifled in your upbringing by adults. It is natural and normal and preferable to express who you are and accept that other people also have that right. We don't have to like others and they don't have to like us, but we have no right to shut up assertive people because we lack that ability to express ourselves openly and directly.