These are some my favorite books that significantly help shape my career as a successful freelancer. I've used the many techniques and advice in these books to improve my skills and increase my income.
I believe every freelancer must learn how to sell your services to become exceptional. This will come in handy in that process.
Human mind is an incredible part of our body and this book will help you take control of your decisions by learning to train your subconscious mind to find success and live a happy life.