A few of my favorite short business books that are great for a business owner looking for concrete action ideas in a concise well written form:

Seeing The Big Picture – Kevin Cope, A great introduction to business financial fundamentals. Learn how to read financial statements, and highlights of what to pay attention to.
Good story style illustrations of an imaginary business to accompany each section’s points.

Cadence: A Tale of Fast Business Growth – Pete Williams, entertaining, relatable story format about making small steady consistent improvements in several specific areas ‘the seven levers’ toward doubling profits. Great for ‘I’m in trouble, what can I do right away?’

The 1-Page Marketing Plan – Allan Dib. ‘lean’ approach to marketing efforts.
I love the intro’s directness- ‘This book is about how to get you to profitability ASAP’

Startup CEO – Matt Blumberg, great for those starting out, or in business for a while having trouble with growth and culture, and have lost focus (or never knew) ‘the three duties of a CEO’ (which aren’t just Matt and his well known CEO friends’ idea- I once independently verified them with a well know VC during a Q&A)

Quickbooks for Dummies (yes really, it helped me quite a bit 😊)

Slicing Pie – Mike Moyer. For a pre-money startup, how to fairly track and allocate ‘Who did what and what’s my share if we ever get funded?’. GREAT set of rules including many situations you might not think of, or that are uncomfortable to discuss- many real examples are provided. It’s great to have an independent set of rules you can all agree to follow. It’s worked well when I’ve used it.