Remember to call 911 for any emergency (emergency is anything where a life-threatening situation exist or a serious felony is in progress) call to report a fire, crime, medical emergency or any other situation requiring an immediate response by a police, fire, and EMS). You also call 911 for any non-emergency or police report (non-emergency a crime has just occurred of a non-life threatening nature and immediate response is not needed or doesn't require a rapid response to prevent injury or property damage) situation that is needed.
Remember during high call volumes the dispatcher will ask if this is an emergency or non-emergency. If it is a non-emergency they will place you on hold so they can answer another line that might need immediate attention.
Try and remain clam while listening and answering questions from the dispatchers. If left to speak uninterrupted, many excited callers will go to great length and detail in describing what has lead up to the incident and that is left to the first responders to investigate.
Know your location, as some VOIP and cell phones will not give the dispatchers an address.
Remember while the dispatcher is gathering the needed information, first responders are being dispatch behind the scenes by another operator simultaneous.
Try to remain calm, Answer all questions (they are necessary and do not impeded response time). Follow all instructions given by dispatcher. The more specific or detailed you can be the better able we are to assist.