Denied unemployment, how do I appeal? - what worked for you?

I got a denial letter last week saying I left my job voluntarily, but I was let go as a recruiter. This is my first time dealing with any of this. The letter lists a deadline and a hearing process, but it is hard to follow. Did you bring documents or only talk?

Stay calm and stick to facts. Mine lasted about thirty minutes and felt more like a conversation than a trial.