Start with the Basics of learning the concepts.
This is one of my favorites because it is easy to understand the various concepts: Ethics for Massage Therapists (LWW Massage Therapy and Bodywork Educational Series) Gorgias Press ed. Edition. It is a bit outdated with the info on associations but the basics of ethics is really clear.
The Ethics of Touch is also a good basic book on Ethics and has been around for awhile and revised. Written by Cherie Sohnen-Moe who is also the author of Business Mastery, has been a long time leader in the massage profession having led the way with this Ethics book as well as creating the Alliance For Massage Education.
In-Depth Ethics Books
To really understand how ethics is really the basis for a successful business, you will need to understand things like the therapeutic relationship, transference and counter-transference. Many are taught that those things should be avoided when in reality they cannot be and are an essential part of the healing process. Everything revolves around boundaries.
Burnout is another thing that is also talked about as a thing to avoid for self care when it really can be something you go through to learn about yourself and yes…about boundaries.
The Educated Heart : Professional Boundaries for Massage Therapists and Bodyworkers (originally written by Nina McIntosh who handed it over to Laura Allen). Great resource for understanding boundaries and how to apply them to daily business practice.
Keeping the Professional Promise by Cidalia Paiva, PHD is also a favorite of mine but I can’t find it anywhere. Here is one of her articles on creating your own code of ethics (on Massage Therapy Canada). She was an instructor at West Coast College of Massage Therapy for over 20 years and holds a Ph.D in Philosophy with a specialization in Medical Ethics.