This is a good book with lots of things to consider. It is good supplemental reading if you decide to take a USCCA (U.S. Concealed Carry Association) course.
It helps give you things to consider / ways to "think." Just remember, like anything else: When it comes to "do it yourself" self defense, practice and training "from outside" is hard to replace.
This book is much like others such as: "Deadly Force," and "Concealed Carry." They are all good and they all cover much of the same information. Each of the 3 has a few "unique" things of their own.
I would still suggest you consider 2 training courses:
1. For Marksmanship, the NRA Basic Pistol course.
2. For Self Defense, the USCCA course.