Where do I start? Those people that take the time to think about things, will always ask this question. You know what you need to be self-sufficient, but jumping in, and tackling everything is bad.
If you have the land, I always suggest starting with gardening. It is the simplest thing to do, and rarely does any one die doing it.
Finding the perfect spot will be a trial and error situation. First look at your grasses, where ever they are plush is were you are going to want your garden. However, keep note of where the grass isn’t so plentiful, these areas are perfect for things like grapes and sweet potatoes. You can also take soil samples to your local extension office, and for a small fee they will test it to see what you need to add. If you plan on using a piece of land near a road, please get it tested for lead.
Urban folks might want to look through your local paper or online want ads and see if anyone is offering up an empty lot for use. You can always place an ad yourself, willing to barter or crop share for use of the empty land. Make sure the soil is tested.
I realize that it is late in the season for starting a new garden talk, but actually the fall is a perfect time to start planing. You can still get an idea of where you can plant in the spring, and with the knowledge of your soil, you can begin ordering seeds in January, when the bulk of seed catalogs start arriving.
As for seeds, I would stay away from anything GMO. I would stick to heritage, or f2 Hybrids, even F1 open pollination hybrids are fine to use. This way you can seed save and know what you will be getting the next year. Buy only the things you know you will eat the first year, after that gradually add new and exotic sounding veggies to your garden.
Make sure your garden isn’t too big. A beginner shouldn’t start with a full 1 acre garden. You will end up overwhelmed and lose too many plants in the process. Possibly giving it up for the season, and the next year.
Look into planting methods, such as 3 sisters, companion and square foot or an all out free for all. See which one sounds best for your situation and try it. If it doesn’t work for you, try again, or try a different method.
You can find more detailed gardening information of my blog, A Homesteading Neophyte.