I wish I read these books on personality types a long time ago. I would have made much better decisions.
These works will give you the superpower of identifying folks so well, you can ensure that only the right people surround you, trustworthy friends. Taken together, these books are the Bible for dealing with people in business and personal relationships:
"Positive Personality Profiles" by Dr. Robert A. Rohm
"Personality Plus" by Florence Littauer
"PRO$PERITY Personality Recognition" by Ron Stickler
"Dangerous Personalities" by Joe Navarro
They all discuss the DISC model, which I find to be the most accurate of all personality models.
Everyone should take an assessment, to see where they stand. The results will determine your strengths and the areas that need improvement.
These books are only the beginning. You should never stop learning everything you can about how people operate from other books, YouTube, search results from Google, etc.
The first two books gives one the fundamentals of the DISC model. Each personality type has several different names. If you're not familiar with this model, here is a brief summary:
Driver or Dominant: direct, results-oriented, task-oriented, competitive
Influencer or Promoter: enthusiastic, people-oriented, attention-seeking
Steady or Amiable: relationship-focused, passive, people-oriented
Compliance or Analytical: detail-focused, methodical, task-oriented
Stickler's book is geared towards salespeople. Once you pin down someone's personality type, you'll know their dominant buying motives. As a result, many have achieved fabulous results.
I have written before about Navarro's book, an excellent treatise on spotting toxic people and how to handle them.
Life-changing information like the DISC model should be taught in every school and by every parent.