Ask questions about anything that is unclear. Put everything in writing, including pet agreements, notices and requests. The lease or rental agreement is the most important set of rules to follow if you have a disagreement. If you buy things like new locks or smoke detectors, if you spend money on repairs, keep the receipts. Make a checklist of conditions of the property, appliances and furniture when you move in.
Some landlords use an inventory and condition form.
Many states require such a form to resolve disputes over deductions for repairs from your security deposit when you move out. Be sure you sign the checklist, then have the manager sign it and keep a dated copy. The dated condition report will be your best defense in any dispute. Keep your payment current as required by your lease. Many tenants are surprised to learn that late rent payments can effect credit in the same was as a late car payment.