Self-confidence is extremely important in almost all aspects of our lives. So many people struggle to find it but it is very precious that no one can get it easily. We have to struggle a lot to get "Self-confidence" and those people are very blessed who have it naturally. Here are some most effective books for "Self-confidence".
i. The Gifts of Imperfection by Brené Brown
ii. The Confidence Code by Katty Kay and Claire Shipman
iii. The Six Pillars of Self-Esteem by Nathaniel Branden
iv. Ten days of Self Esteem by David D Burns M.D.
v. The New Psycho-Cybernetics by Maxwell Maltz, Dan S. Kennedy
vi. The Power of Your Subconscious Mind by Joseph Murphy
vii. Feel the Fear and Do It Anyway by Susan Jeffers
viii. How to Stop Worrying and Start Living by Dale Carnegie
ix. Unstoppable Confidence by Kent Sayre
x. The Magic of Thinking Big by David J. Schwartz
xi. How to Develop Self-Confidence and Influence People by Public Speaking by Dale Carnegie
xii. Presence by Amy Cuddy
xiii. The Confidence Gap by Russ Harris
xiv. The Power of Self-Confidence by Brian Tracy
xv. The Art of Extraordinary Confidence by Aziz Gazipura
xvi. Go Fearless by Atlas Rowe
xvii. Ultimate Confidence by Marisa Peer
xviii. The Ultimate Secrets of Total Self-Confidence by Robert Anthony
xix. The Unlimited Self by Jonathan Heston
xx. Self-Compassion by Dr. Kristin Neff
All of these books are available on Amazon. Pick out one of these books and read it and then try another,another and another. I hope these books will help you somehow.