Employers are generally impressed when an applicant asks insightful questions and may, in part, base an estimate of your seriousness of purpose upon the depth of your questions.

Good topics to ask about include:
The industry in which the company operates
Management style
Challenges of the company
Goals of the company

Generally, it is considered unprofessional to ask about pay or benefits on the first interview. You want to let the company know what you can do for them and not what they can do for you.

Pick your favorite 4 – 5 questions and have them prepared to ask during the interview process.
Why is this position open?
What would you like done differently by the next person in this position?
How many people have held this position in the last couple of years?
What happened to them subsequently?
Why did the interviewer join the company?
Where is the job located?
What are the travel requirements, if any?
What type of training is required, and how long is the training?
What would be your first projects?
What are the skills and attributes most needed to get ahead in the company?
Who is the company’s major competitor?
Who will be the major competitor over the next few years?
What is the company’s competitive edge?
What has been the growth pattern of the company over the last five years?
What has led to the company’s successes over the past few years?
What are the company’s biggest challenges in the years to come?
What type of support does this position receive in terms of people and finances?