Great advice so far

You can also pre-empt a lot of questions by looking at the job ad or description for clues, for instance, a customer service job will mean you'll be asked questions about customer service experience, dealing with difficult people, going beyond the call of duty, teamwork, flexibility of hours and so on.

When I've interviewed relatively inexperienced people in the past, I've also asked questions about what subjects they liked in school, what they didn't like, involvement in team sports, what their longer terms goals are, and what they like about my company/job to break the ice and get to know the candidate better.

Good luck!