Be prepared to explain why you want to leave your current position but try not to portray your current employer in a negative light. You could say you are looking for more stable hours. Or maybe you could say that while you enjoy the 1 to 1 time you get to spend with your patients you miss working in a team environment provided in a hospital. Whatever you say just be sure it is true to your situation.
Also, expect to be asked about how you handle situations. For example, "tell me about a time you handled a conflict with"...coworker, physician, patient, family member, etc...
Figure out what it is about nursing you are passionate or enthusiastic about and find a way to bring it into the conversation. Your enthusiasm or passion will show and something perspective employers are looking for is a candidate who will be engaged in the position and not just there solely for a paycheck.
Another common question is to ask you to describe a situation where you feel you failed. After you describe the situation be sure to add what you learned from the experience and, if applicable, how you have since handled similar situations successfully.
I used to have a long commute to work and I would use the time on the road to reflect on such questions so when I was put on the spot in an interview I would have an answer ready for the interviewer.
Have a few questions of your own ready. I like to ask the person interviewing me what they like most about working at XYZ hospital.
I'm sure you can find other interview tips in the Nursing Career Advice
subforum. Good luck with your interviews and let us know how things are going.