In addition to other questions about your basic qualifications and preparedness for the job, expect to answer the four following questions in some form during your interview process:
"Tell me about yourself." This is a standard first question in interviews allowing you a chance to set the tone of the interview and make a fabulous first impression. Lead with your prepared 30-second self promotion and make brief reference to anything that uniquely qualifies you for the position.
"Why did you leave your last position?" This question is NOT an invitation to bash your previous boss or delve into everything you disliked about your previous position. Rather, provide the honest explanation for why you left (or were forced to leave) with a very positive spin. This is an excellent opportunity to explain your long term goals and how this position will play into those goals.
"What is your biggest weakness?" This question generally follows its counterpart, "What are your greatest strengths?" and provides an opportunity to show off your ability to answer a difficult question on the spot or represent yourself in the face of adversity. Unless you mention a weakness that makes you completely incompatible with the proposed position, your potential employer is not likely to hold these weaknesses against you. We all have our weaknesses after all.
"What questions do you have for me?" Other than allowing you time to clarify any questions you have about the company or the position itself, this question showcases your critical thinking skills and shows the interviewer that you have been paying attention throughout the interview. It is generally considered taboo to ask about compensation, benefits, or scheduling at this point in the interview process, however, if you have make or break issues concerning compensation or flexibility, you can tactfully pose those questions here.