Advice
All the interview advice you read in magazines and hear from the professionals should be followed. Act professionally. If in doubt, be formal rather than casual in your dress, speech and manner. In regards to what to prepare for... have specifics in mind. Exactly what is your classroom management plan? Can you give examples of how you guide students? What would you do with a student who is ________? How do you communicate with parents? Think about how you teach. Be ready to describe a typical math/writing/science/guided reading lesson. Make sure you give examples of things you've done that show your strengths, but don't be afraid to share your weaknesses. However, be ready to explain how you're working on your weaknesses or how you've grown as a teacher.
I long term subbed for almost a year in 3rd grade before getting hired in the following year. Be ready for a mess. The transition is very difficult for everyone involved (the kids, their parents, and you too). What served me best was to stay in touch with the parents. It's so easy to put off that phone call to tell a parent that their kid was disruptive all day or is missing five assignments. However, that phone call is easier (and you'll find most parents really will do what they can to help) than the situation you'll end up with if you let things go. Harsh consequences (no recess FOREVER, suspension, detention...) don't go over well with parents if they had no idea anything was going on. Same thing with academics. Ugly grades on report cards are not appreciated if parents weren't warned early on.
Good luck!