You should select questions that are appropriate for your career field. Here are a few questions:
What are your main responsibilities as a ____________..?
What is a typical day (or week) like for you?
What do you like most about your work?
What do you like least about your work?
What kinds of problems do you deal with?
What kinds of decisions do you make?
How does your position fit within the organization/career field/industry?
How does your job affect your general lifestyle?