Evidence typically presented at an appeal hearing includes oral testimony from you and from witnesses, and documentation such as letters, business records, phone bills, etc. that you can use to substantiate your version of events. If this evidence is in your employer's possession, you can ask the administrative law judge to subpoena the records. A judge can also issue a subpoena to an individual witness to require them to attend the hearing and testify. You can bring notes with you to the hearing. You will want to bring multiple copies of any documents that you want to present as evidence to be able to give to the judge and the other side.