The Great Mental Models: General Thinking Concepts [Volume 1] — Farnam Street

With infinite amounts of knowledge at hand, learning how to think is perhaps the most relevant skill you can develop. No matter where you live, how you earn a living, or what your interests are - this book will help you analyze & assess the world around you by cutting out the noise & focusing on what is important.

Here's an excerpt from the books introduction:

"Chunks of knowledge from different disciplines that can be simplified and applied to better understand the world...they help identify what information is relevant in any given situation."

"Devastatingly useful in practice." 

The author's learnings are documents at fs.blog if you want a digital preview of the contents of this book.