I'm sure there are threads somewhere with more help, but I sit in on interviews and hear what my boss will ask.
First of all, I think it's ok to have weaknesses. Nobody is perfect. I think admitting and realizing you do have weaknesses goes a long way in the interview. It's how you deal with them is what will or won't impress the person interviewing.
Ok..questions I have heard...
How would you handle a CNA that is insubordinate?
If a co worker isn't pleasant to work with, how would handle that?
A pt crashes with XYZ...tell me what you would do?
Tell me about a time where you had a good patient outcome.
One thing that is a deal breaker for my boss is somebody never asking questions about the facility, ratio etc.
Act like you want to work at this facility because you believe in it. Not because it's 'just a job'.
Know the history of the organization, down to the mission statement. Managers like stuff like that.