The Humane Society has a First Aid guide:

http://www.hsus.org/pets/pet_care/dog_care/your_dogs_first-aid_kit.html

Everyone who shares a home with a dog should have a basic canine first-aid kit on hand. The HSUS recommends including:


* A good pet first-aid book
* Phone numbers:
o Veterinarian
o The nearest emergency veterinary clinic
o A poison-control center or hotline
* Paperwork:
o Proof of rabies vaccination status
o Copies of other important medical records
* Rectal thermometer (your dog's temperature should not rise above 103°F or fall below 100°F)
* Sterile gauze rolls and pads for bandages
* Adhesive tape
* Hydrogen peroxide
* Rubbing alcohol (isopropyl)
* Over-the-counter antibiotic ointment
* Epsom salts
* Tweezers
* Petroleum jelly
* Antiseptic lotion, powder or spray
* A Nylon leash
* A carrier for small dogs
* Cotton balls or swabs
* Splints and tongue depressors
* Towels
* A muzzle or strips of cotton to prevent biting
* Penlight or flashlight
* Scissors
* Needle-nosed pliers
* Ice pack
* Plastic eyedropper or syringe
* Sterile saline solution
* Glucose paste or corn syrup
* Styptic powder or pencil (sold at veterinary hospitals and pet supply stores)
* Latex gloves
* Ear-cleaning solution
* Nail clippers