What is your call back number (in case the call is dropped - especially if using a cell phone)
What is your emergency (what you are reporting)
If you are reporting a medical emergency, the medical dispatcher will ask you questions regarding the injured or sick person. Be assured that while they are asking you questions, another dispatcher in the room is sending the paramedics to your location via the two way radio
If a crime is involved, and you saw or can see a suspect be prepared to give a description:
Sex, race, age, height, weight, hair color/length, color of eyes
Other pertinent information such as scars, marks, tattoos
Vehicle description if necessary (license plate number, color, year, make, model, style, 2 door or 4 door, how many occupants, and other features that stand out (dents, stickers, missing parts, etc)
Last known direction of travel of suspect(s) and/or vehicle(s)