Foods to store in an emergency are canned goods, freeze dried goods, nonperishable goods and water. The beauty of canned goods is that they are just about everything; from juice to meats to veggies. When stored properly, they can last decades and viritually indefinitely.
While canned goods are the most easily accessible, the option to grow your own produce and freeze dry or vaccum seal it can be very efficient. While not everyone has the space for a full garden, small greenhouses or potted plants can slowly build up your supply of veggies and fruits to store away.