Continue to learn about the company. Read newspaper articles, magazines, news videos, etc.
Keep note and write down what you learned.
After the interview, follow up with a thank you note to the interviewer and or the company.
Review everything that happened in the interview and make sure this still the job you want and the company you want to work for.
Show that you are truely interested in the position and not just in it for the money or just because you need a job.