What is the diet of a possum?

There are people who are licensed to take care of abandoned animal babies. Contact one in your area. Are these Org. listed somewhere, by Areacodes or Zipcodes, so when and if you have an emergency you can find the nearest one that can help with the type of animal that you may have found? If so, that would be really helpful. If anybody knows anything about a listing, or a number that could get you in touch with someone who could help, please add to this info. Thanks