Denied unemployment, how do I appeal? after 5 years as a call-centre agent

I got a denial letter last week saying I left my job voluntarily, but I was let go as a call-centre agent. The letter lists a deadline and a hearing process, but it is hard to follow. If you have appealed before, what helped you prepare?

Thanks for writing this out. I went through something close to it last year, and it got easier once I kept a simple log of every call and form.

File the appeal before the deadline, even if you are unsure. You can gather documents afterwards. That is the one part I would not wait on.