Yourself! BE yourself. Dress in business attire (not necessarily a suit, unless you're interviewing for an administrative position). Yes, I've seen potential interviewees show up in 'torn' jeans and sandals🤦🏽♀️. Bring a copy of your resume, just in case. If references weren't included, but referred to in your resume, I'd bring those references with you. Also bring any certification cards, ie: CPR, ACLS, NRP, current nursing license, etc that might be appropriate to the position you're applying for. If you've worked several areas or different jobs, be able to explain them and why you changed jobs, etc .. either going to school, relocating, etc. Be able to explain what you feel you'll be able to bring to the unit as far as experiences, and possibly answer how you might handle potential situations that might arise in your working environment. You may be given an example of a situation and asked what you would do to handle it. Good luck in your job search. 👍
Check with the site/hospital to see if they have that information. Some hospitals will request you come in scrubs so that you can shadow a nurse on the unit.