These are from http://blog.asmartbear.com/startup-business-plan.html where they are expanded on and put in context.
I strongly recommend you go to the source - the questions alone aren't enough.
- In one sentence, what does your product do and who buys it?
- In one sentence, why does someone buy your product?
- What one thing is most responsible for preventing sales?
- What's one thing you could do to get more feedback from customers, potential customers, or sales you've lost?
- If you had zero revenue from now on, on what date would you run out of money?
- If someone handed you $100,000 today, how would you spend it to maximize future profits?
- If you were forced to hire someone today, how would you define her job such that she would contribute enough revenue to cover her expense?
- Which of your business operations do you hate?
- What initiatives could be done half-assed without significant impact?
- If you could get one solid hour of advice from a guru you respect, what would you discuss and what would be the goal of the meeting?