Notes from the FEMA
(Federal Emergency Mgmt. Agency)

Long-Term Food Supplies

"In the unlikely event of a military attack or some other national disaster, you may need long-term emergency food supplies. The best approach is to store large amounts of staples along with a variety of canned and dried foods. Bulk quantities of wheat, corn, beans and salt are inexpensive and have nearly unlimited shelf life. If necessary, you could survive for years on small daily amounts of these staples.
"Store wheat, corn and beans in sealed cans or plastic buckets. Buy powdered milk in nitrogen-packed cans. And leave salt and vitamin C in their original packages. Rotate Vitamin C every two years."

Lumen Foods' Home Page Food Storage Principles