There are many companies who will sell you pre-packaged long-term food storage. They're great companies and we even own some of their products. If you want to pack your own food...here are some suggestions:

1. Mylar bags are great. They are the same as the Mylar balloons, only thicker. Many dry goods like rice, noodles, and beans can be packed successfully in these. Insert an oxygen absorber (which does exactly what it says). If you don't own a sealer, you can use a clothing iron and seal your bags against a wood 2' X 4 '. An average 1 gallon Mylar bag needs, at least, 1 300cc oxygen absorber or more. Once sealed, the oxygen absorber will compress the bag into a vacuum seal. Label your bag with: product, packed date, (I also write the use by date). You may also want to write cooking instructions on the bag.

2. The next method I use is sterilizing 2 liter soda bottles. (Any shelf stable bottle that is PETE plastic is safe. Check to see if the recycle triangle has a #1 inside it. If it does, the bottle is good to use for this method.) Rinse your soda bottles. Fill with 1 tsp. regular bleach and hot tap water. Let sit for 2 minutes. Pour out and rinse. Bleach the lids in a similar manner in a side bowl. Let set upside down until 100% dry. (This usually takes 3-4 days. I place mine upside down, on a towel, iside a laundry basket.)
Once your bottles are dry, drop in a 300cc oxygen absorber. Using a funnel, fill with your dry goods: rice, oatmeal, beans, etc. Screw the lid on tight. Within a day, you should see the sides of the bottle begin to compress.

A quick Amazon search brought up this site: 1 gallon Mylars & 300cc oxygen absorbers

*** Note ***
When you open a package of oxygen absorbers, they begin activating immediately. Remove what you need and close up what you don't need. If you have a Mason jar, close them up in one of those. They'll use what little oxygen is in the jar, but they'll still be good to use later. If you can re-seal them with a Food Saver, that would be even better. 

What do you guys think about the oven method using canning jars for flour and cornmeal??

I did it for LTS...48 quart jars. 

Committed,
I'm fascinated! I've done traditional canning and even vacuum sealed my lids with a Food Saver adaptor, but this is new to me. I assume you place plain flour and/or cornmeal in the jars and heat them in the oven until they seal. (?)

Do you have a DYI link?

BTW ~ Welcome to the forum. :) 

Lisa Bedford has made an excellent "how to" video on using a Food Saver to vacuum seal dry goods in Mason jars.

Here's a list of items I've personally sealed:
nuts
beans
chocolate (Toll House morsels)
shortening
tea bags
sweetener packets (Truvia, Splenda, etc.)
hot chocolate mix
Tang
lemonade & Kool Aid mixes
Gatorade (store bought and homemade)
dehydrated fruits (strawberries, apples, bananas, etc.)
dehydrated veggies (mushrooms, onions, celery, etc.)
dried herbs (too many to list)
Meal in a Jar (I have my favorite dry potato soup mix in 1 quart jars)

Another suggestion:
Ball makes 64 oz. jars with a wide mouth. They can be vacuum sealed using the wide mouth adapter. You can purchase them through Ace Hardware. They’re a little over $2 per jar and can be delivered to your local Ace store with free shipping.

(One of my 64 oz. jars has 2 packages of Hershey’s mini assorted candy bars packed in it. I grabbed them on sale about 2 years ago and seal those little treasures up tight! I’m tempted to write “Emergency Chocolate ~ Break when SHTF” on the jar! LOL ;) )

Ace Hardware - 64 oz. Ball jars



Source: The Survival Mom