Make sure you've got all your documents required for legal driving (license, registration and insurance)
Jumper cables are good.
Cell phone
A jug of pre mixed antifreeze can help if you overheat.
If you live in a snowy area bring a shovel along. Entrenching tools from an army surpluss store are a good choice.
Make sure you've got a spare tire in good condition.
Congrats 17pdr-my daughter has those P signs and put them on the front and back of the car-they are like the L signs! The only thing is one blew off the car and landed somewhere lol