Baby foods are ridiculously simple to make. I have only purchased a few jars of baby food since my son was born in 2006. Usually those were in the case of travelling. Each time I tried to get my kids to eat them they were not happy with what I was trying to put in their mouth. I have never been happy about the jacked up price.
Anyway. Back to the matter at hand. The process of making baby food is simple.
-Select raw or cooked food you desire to feed baby
-Mash or grind
-Feed to baby
I store unused portions in either a baggy or a small container with a lid. I can't speak to freezing the extra because I have never done it.
A note on baby cereals in my baby food posts. I use baby oatmeal. Feel free to use what works best for you and the children you are feeding.