Your best bet is college textbooks. This one is good: http://epp.etf.rs/wp/wp-content/uploads/2018/03/Fitzgerald_E...

Less on machines on more on basic concepts, may I recommend a physics site that is spiritually related to this website, in that it is also clear, simple, and in many ways a work of passion for teaching? http://hyperphysics.phy-astr.gsu.edu/hbase/emcon.html#emcon

Electric Motors and Drives[0] is very good. Not very mathematical, and gives a lot of intuition. If you understand basic electronics and can do arithmetic you can follow most of the book. Some parts are harder than others but if you keep going it will eventually make sense.

Edit: I took a look at some of the other books people recommended and they seem more advanced, this book is easier than them and probably better for someone without an EE background. I am not sure how to best learn electronics (I learned from The Art of Electronics, but that is probably not the easiest way to learn, and probably overkill for just learning how motors work.)

[0]: https://www.amazon.com/Electric-Motors-Drives-Fundamentals-A...

Starting from roughly zero, I'd recommend this page and its neighbours:

http://info.ee.surrey.ac.uk/Workshop/advice/coils/force.html

https://www.amazon.com/Electrical-Technology-H-Cotton-ebook/... an older edition of this was my textbook back in the day. You can only understand motors with this book. You'll also need a textbook on power electronics to learn how to supply them electricity. Maybe a textbook on control systems to learn how to control them.

Electric Machinery Fundamentals Stephen J. Chapman

This was the book we used in undergraduate, It was quite readable as I remember.

for ac machines, langsdorf.

I saw a recommendation for the Art of Electronics by Paul Horowitz on here a while ago.