I'd have something on your coaching philosophy ready. Here are some of the more interesting ones I've been asked...
1.) If we name you head coach, what are the first 5 things you would do?
2.) If we attend a practice, what will we see?
3.) If we attend a game, what will we see?
4.) If you are outside right after school and it starts raining, baseball, softball, and soccer all need the one gym, how will you determine who gets it?
5.) Describe your process for selecting the team?
Hope that helps.