Got a denial letter for unemployment, what now?

I got a denial letter last week saying I left my job voluntarily, but I was let go as a bookkeeper. I have read a lot of threads here and could not find my exact situation. The letter lists a deadline and a hearing process, but it is hard to follow. Did you bring documents or only talk?

Keep everything in writing and save the confirmation numbers. It made the follow-up calls so much easier.