This book, by Madonna Woods, describes how chords are based on scales and how they are built.
It is not a book about playing scales. Instead it looks at the full keys and scales, one by one, and clearly illustrates the key through the scale. It teaches how chords are constructed from each note of the sclaes and illustrates which chords are going to be the main chords of any key, and why.
It teaches you to understand chord construction within the key. It covers all 12 major keys with all 7 chords of each key and explains it all in such a way you can see, instantly, how it works.
If you play in different keys and would like to understand how to tell what chords are going to be found in what keys, this course is for you.