In addition to having a hard copy in a binder, I find the following useful to have pre-programmed into your phone:
Address and phone number of local hospitals (EMS may be overwhelmed). Know which hospitals are the best at trauma, pediatrics, heart and stroke treatment. That might be four different hospitals in your area or it might be one or two.
Address and phone number of your pharmacy along with the address and phone number of a 24 hour pharmacy.
Address and phone number for your vet, animal hospital, and kennel. A copy of your pet's shot records may be critical to getting your pet into a kennel or emergency shelter.
Addresses and phone numbers of at least three friends that would let you crash at their place if you had an emergency, ideally some will be able to accommodate your pets, too.
A list of hotels with numbers that will take pets.
Phone number to your insurance agent(s).
Also in the binder:
A photocopy of everything in your wallet, front and back.
A copy of your passport.
A copy of your birth certificate.
A copy of your homeowners policy.
A copy of all your bills updated once a year (or more, but all you really need is the account numbers and 800 number).
An encrypted flash drive with your family photos, resume, scanned copy of your tax returns from the previous year, pictures of all valuables showing the serial numbers, a video showing belongings in each room of your home, every dresser drawer, closet, etc.
A checkbook.
Cash.
A list of all prescriptions for every family member along with an overview of their medical history (past surgeries, injuries, serious illnesses, vaccination records). Having a page for each family member that you can tear out and give to the doctor or paramedics is a real time-saver and may provide critical information at a time when a loved one can't speak for themselves.