There are Stupid Questions

Ask appropriate and well-thought-out, relevant questions during the interview.

The common view of a job interview is that the candidate patiently sits by, responding to questions asked by the interviewer.  That view is certainly appropriate and occurs in every case.  However, the candidate should come equally prepared to ask relevant questions in return.  The key for the candidate is to ask relevant questions.  Questions asked that have already been answered shows an immediate lack of listening.  Questions that should have been answered through basic pre-interview research show a lack of preparation.  Your questions may reveal more about you than your answers.