People are always looking for a new way to memorize vocabulary, understand grammar, to learn a language. Everyone has their own experience and methods and sharing how you learn can help others. Personally, I enjoy learning from books. I hope this short list of books about how we learn will benefit not only your Chinese studies but everything.
1. The Language Instinct
You won't find a better book to describe what language is and how we learn it than The Language Instinct. Steven Pinker, a Professor at Harvard, approches the topic with simplicity in an engaging way.
2. Chinese Grammar Wiki
Chinese Grammar Wiki is written by John Pasden so it provides a very practical perspective for fellow foreigners. The book is available in paperback or online: https://resources.allsetlearning.com/chinese/grammar/Main_Page
Disclaimer: Grammar books are more like a dictionary, to reference grammar rules and exampless. Please don't try to learn a language by reading about grammar, that's for linguists, not for use in the real world. The best use of grammar books is to look something up if you're confused.
3. Peak: Secrets from the New Science of Expertise
Every one knows we need to practice in order to learn. The quesion is HOW? Peak shows us an answer that we can trust. Using plenty of evidence from the authors's research, they tell us that we need special practice to improve a skill. I've read this book several times and apply it to teaching Chinese.
4. Learn More, Study Less
Peak shares the principle but Learn More, Study Less tells us the specific techniques. Actually, you could find hundreds of books to tell you how to study. I choose this book because it's simple and short. If you want to learn more about how to learn, here's a online course provided by University of California San Diego: https://www.coursera.org/learn/learning-how-to-learn
5. How People Learn: Brain, Mind, Experience and School: Expanded Edition
This book is an acdemic report discussing the problems in American schools. I shared this book because people working in a language or Chinese school will encounter the same problems. This book also gives us solutions to these problems. It's a long read but worthwhile.