Denied unemployment, how do I appeal? - any advice?

I got a denial letter last week saying I left my job voluntarily, but I was let go as an IT help-desk technician. I have read a lot of threads here and could not find my exact situation. I have not done a hearing before and I am nervous. If you have appealed before, what helped you prepare?

Keep everything in writing and save the confirmation numbers. It saved me later.