Discovering Transactional Analysis may well change your life. It certainly changed mine.
This book provides a very accessible and readable introduction to transactional analysis.
However the book is dangerously out of date. It was written in the 60s and has not been brought up to date.
What I found out after reading this book and getting really interested in TA is that in the 60s TA went through a period where it was adopted as a kind of pop-psychology and a number of books were published which are now regarded as over-simplified. Also TA has moved on a lot in the last 30 to 40 years and there are now widely accepted theories and techniques which were not around in the 60s. A much more modern book is TA Today : A New Inroduction to Transactional Analysis,Ian Stewart, Vann Joines . Which I would recommend in preference to this book.