I think the best question you can ask is "what do you think I should do to meet my goal X" for whatever value of X.
I guess it can't hurt to ask questions like "what books influenced you," as someone else answered. Except that it wastes your valuable time with this person. If this person thinks a book was instrumental enough to make a difference for you, they'll certainly mention it.
1) What people, books, events, experiences, etc have most influenced you? 2) What’s your daily schedule like, from waking to sleeping? 3) What are some things that may help me get from where I am to where you are? 4) What are the foundational skills necessary to achieve at your level, and how to you practice them? 5) Do you ever regret your career choice or path? Or what are some of the worst parts of your career?
Hope these help at least a little!
2. Ask what the most difficult situation was that they had to deal with lately in $area; how they approached it; how that worked out; what advice they’d give someone in a similar situation