Find out all you can through personal contacts, written materials, the Internet, etc. Assemble your interview attire. Always dress neatly and conservatively, keeping the interviewer in mind.
First impressions do count.
Stress your best qualities and what you could bring to the position in a positive manner. Don't leave without them knowing you are interested in the position. Finally, ask what the next step in the process is and when you could expect to hear from them. If you do not hear from them after a set time, phone or write to find out where they are in the process. But before you accept, evaluate the terms.