Review these tips, as well, for what you should avoid talking about during job interviews so you don't inadvertently ask the wrong thing and knock yourself out of contention for the job.
General Rules about Asking Questions
Avoid "Me" Questions
"Me" questions are those that put yourself ahead of the employer. These include questions about salary, health insurance, vacation time, work hours per week, and other concessions. During an interview, you are trying to demonstrate to the employer how you can benefit the company, not the other way around. Once you are offered a position, you can begin to ask what the company can do for you.
Ask One Question at a Time
Avoid multi-part questions; they will only overwhelm the employer. Each question should have one specific point.
Avoid "Yes" or "No" Questions
Most questions with a "yes," "no," or other one-word answer could likely be answered by searching the company's website. Instead, stick to questions that would create a dialogue between yourself and the employer.
Ask Questions About Multiple Topics
Avoid asking questions about just one subject. For example, if you only ask questions about your manager and his managerial style, the interviewer may assume you have an issue with authority figures. Ask questions about a variety of topics to demonstrate your curiosity and interest in all aspects of the position.
Nothing Too Personal
While it is a good idea to try to establish a rapport with your interviewer, do not ask personal questions that are not public information. For example, if you see college banner on the employer's wall, you can certainly ask if he went to that college. However, avoid overly personal questions about the interviewer's family, race, gender, etc.