Who does the hiring? DON or HR?

I'm a recent CNA graduate who is looking for a job here in CA...

When I call/contact a hospital to inquire about openings, who is the best go to person?

The Director of Nursing? The Human Resources dept.?

p.s. I'm not necessarily looking for a CNA position; patient tech is fine too, is that still under the nursing dept.?

Thanks in advance for your help!