I went on an interview a while back, and I was frightened out of my wits... but my roomie helped me prepare by telling me that there are 3 questions every interviewer asks:

1. Why are you leaving your old job?

2. Why are you the best candidate for this job? i.e. what skills do you possess that fit this job

3. I can never remember the third. This is perhaps why I haven't got a new job.