AAA is the American Automoblie Association and is an automotive club that you join and renew once a year. It covers you for things like needing a jumpstart on the battery, running out of gas (1 gallon), locking the keys in the car, changing flat tires, etc. It doesn't have to be your car, it can even be one you're riding in!
A lot of hotel/motels offer AAA discounts to members. AAA also have travel services, financial investing, etc.
Check out the site at
www.aaa.com and you will find out everything you need to know.