Testimony: What a witness swears to, either in court, by deposition, or by affidavit.
Transcript: A written record of testimony or other spoken words.
Trial: This is the presentation of evidence and argument to a finder of fact.
Trial brief: A written memorandum which you give the judge just before trial begins. The brief should outline specific important facts you expect to prove and important arguments you expect to make. This would be a good time to point out legal authority (cases or statutes that say the court should do what you want it to do) for positions you expect to take during the trial. If you think the debt collector is going to try to introduce evidence which violates the Rules of Evidence, you might make your argument here first. But note: making the argument in a trial brief is not enough to preserve your rights; you must make all arguments and present (or attempt to present) all evidence at trial or you lose your right to do so. The trial brief is just an opportunity for the judge to take a little more time to think of the issues you want to present before the trial begins.
Trial docket: A list of cases that will be tried on a particular day, week, or two-week period. Normally you will see the judge on the first day of the trial docket (if your case is set for trial), and the court will figure out when the trial will actually occur. In Associate Circuit cases, where trials are usually pretty short, you can get a fairly good idea of when you will need to be ready to start. In the Federal Courts, on the other hand, you might have to be ready to start at any time during a two-week or longer period, which can be much more difficult to manage.