This book made proof based math approachable for me. There are mechanical aspects to proofs that are probably best practiced in a structured way and this book does that by also acquainting you with set theory.
I have seen "How to Prove It" on Hacker News multiple times! I did a similar question about Discrete Math a month ago [1]. Someone also suggested this book. It is on the top of my "to read list". One of my friends says this book is his favorite one. [1] https://news.ycombinator.com/item?id=16355825
