At move-in, document any and all issues and damage to the property using a move-in checklist. Make a copy of the checklist for your records and provide a copy to your property manager within the first seven days of the lease term. You could be held responsible for pre-existing damage and possibly lose your security deposit if you do not document pre-existing issues and damage.
Take pictures so that you have visual documentation of any pre-existing damage (preferably prior to moving in furniture). Email the pictures to your property manager with the move-in checklist. This ensures that timestamped documentation is on record.
You also may want to video record the entire unit in one recording (do not stop or pause at any time). As mentioned above, after you record the rental unit, email yourself and your property manager a copy of the video so that you have the date and time of the recording.