The Startup Owner's Manual

Steve Blank's blog (not a book, I know) + The Startup Owners Manual also by Steve Blank. Lean Product Playbook by Dan Olsen. The two helped me understand what it meant to 'get out of the building'. 7 Powers + Good Strategy Bad Strategy helped me think long term about the business model and evolution of the company.

Thinking, Fast and Slow - Daniel Kahneman. Learn why we're fools by nature. Incerto - Nassim Nicholas Taleb (4 volumes, with The Black Swan as my favourite). Learn how not to be a fool, or at least, minimize its impacts. The Startup Owner's Manual - Steve Blank. Learn how to find your way through the market.