what does a nurse manager/administrator do?

Good lord. This answer could be miles long, but I'll try to make it short. It won't include ALL the things I do, but it will hit some of the high points!

As the Director of Nursing Services I....

Manage the largest budget in the building. That means I manage overtime, meet state minimum staffing requirements and our facility requirements, manage costs while providing all the needed items for the residents, and buy new equipment, while staying in budget.

Hire, fire, and coach staff. I hate firing people, but I don't tolerate poor care, and if you're giving it, you're gone. This involves supporting my Unit Managers and Shift Supervisors in their coachings.

Manage clinical programs so that we are following our management consulting company's programs to the letter. This includes auditing, educating, and daily analysis of how the systems are working.

Ensure all Federal and State regulations are followed in the provision of care. This involves knowing the regulations, auditing, and ensuring and monitoring the systems we have in place.

Quality Improvement. Monitor clinical indicators, quality indicators/quality measures and facility benchmarks for falls, wounds, restraints, psychotropics, etc. Work directly with the Risk Manager to put Performance Improvement Plans in place, then monitor those for compliance.

That's a quick rundown, and by no means conclusive.

Good luck

I'm a bit late in responding, so this probably won't help you, but I wanted to add as a floor manager I did essentially the same as the Director above listed, which makes me wonder what OUR Directors do, LOL