Specifically - Store Beans.
In addition to grains, The Church of Jesus Christ of Latter-Day Saints recommends beans for longer-term storage. Beans are a fantastic protein source and are the perfect complement to many of the recommended grains. In fact, beans and rice (or beans and cornbread) make a complete protein which is full of amino acids and all sorts of good stuff. Our family really likes black beans and refried (pinto) beans -- so that's what we've stored.
Beans are not cheap. I've seen them recently for about $50 for a 25 lb. prepacked bucket. The church cannery offers them for around $5 for a #10 can. They have black, pinto and white beans. Beans are also available in bulk bags from the home storage centers for approximately $16 for 25 lbs. The Provident Living website states that beans can be stored for 30 years or more in ideal conditions.
You should store 5 lbs. of beans per person per month (45 lbs for a 9 month longer-term supply -- 60 lbs per person for a 12 month longer-term supply).