Documents: bring ALL relevant documents with you. Even if you "think" you may not need them. ORIGINAL documents. ORIGINAL contracts. TITLES or ownership papers. Photographs. Written estimates. PAID bill receipts. Credit card statements. BANK statements. Lease agreements. Cancelled checks. Bring it ALL.
Why originals? They are the "best evidence". Copies of documents are just got as good, and, in some circumstances, are not useful at all. If you do not have an original, you will need to explain why- and that explanation is subject to scrutiny.
If you are bringing photos, you must know by whom they were taken, when they were taken, and where they were taken. Do they accurately represent the item in the photograph at the time of the event in dispute? If you did not take the photos, bring with you the person that did take them.
Witnesses versus a written statement by a "witness"
Bring any witness you need to with you to court! Do not rely on a statement by the witness on paper, even if it is sworn into an "affidavit".
Organize your documents!! Chronologically. Alphabetically. By witness. By item. Have some order, so you are not weeding through papers at a trial when you are before the judge.
Most importantly, try to stick to the facts and leave emotions out of it. The Court wants to here and view the case, not family history or bad blood.