Reddit reviews Industrial and Organizational Psychology: Research and Practice

https://www.amazon.com/gp/aw/d/0470129182/ref=ya_aw_od_pi?ie=UTF8&psc=1

That's a good overview book to get introduced into the topics. It's very high level, easy to read, and makes the information understandable to people outside the field.

You don't need to know any business related stuff really. You'll learn what's relevant to the field as you go, but you don't need to have a degree in business to get in.

Good luck!