If there were only one book I would recommend to business owners, “The One Thing,The Surprisingly Simple Truth Behind Extraordinary Results” is it.
This book clearly walks through what focus is, why it is important and how to achieve it in practical terms. As a bonus, it’s a quick read!
The specific questions laid out in “The One Thing” aren’t exactly the ones I’ve used through the years, but they are good and the entire approach is so similar to what I’ve found works through the years, that as I read it, it made me wonder if the authors had been inside my office (or mind).
I read it on loan from the Columbus Library, but of course “The One Thing” is also available from Amazon. (I have not been compensated in any way for my review of this book, and those are regular links, not affiliate links)