There isn't much you can do garden wise in January : (
If you're really feinding you can sprout your sweet potatoes and grow long shoots for later splitting.
Or you can dig you favorite roots of wild greens like poke, or dock for sprouting indoors in a bucket.
Otherwise you can plan your next years approach. Here are my suggestions on strategies, and on some good sources for your food providing plants.
For seed -- certainly seed is available everywhere, but if you want some unique varieties you've got to look around a bit.
http://www.seedsavers.org/ These guys are committed to saving heirloom plants and seed collections. It's a great place for variety in your garden
http://www.rareseeds.com/ Baker creeks catalog is a work of art. Fantastic pictures and racy political commentary make this one a spicy read. It inspires me to get some great looking heirlooms.
http://www.gourmetseed.com/ Gourmet seed doesn't have all the flash of baker creek, their catalog is mostly words. They do however deliver a large quantity of seed in their packets. And that makes up for it and then some.
Perennial no maintenance plants -- $2 for 2 apples you say at the store!!! You could buy an apple tree and get all you want forever. The same is true of so many easy to grow maintenance free plants.
Tree Strategies-- For any tree, I suggest you get the biggest one you can afford. The only exception would be peach. Even if you don't like your variety, you can graft it into whatever you want (I'll post later on that in march) If you have limited space, google image espalier Finally check out when they produce their fruit. You can stagger some producers that go super early to late fall.
Fruit tree suggestions
Peaches -- 4 years till you get peaches, they grow for about 18. There's yellow and white flesh. You can go from seed, but the seeds don't sprout every year so you may get them the next or the year after.
Apples -- I suggest getting heirloom varieties from the nafex list, a neighbor, or this guy http://www.greenmantlenursery.com/fruit2008/fruitordering-info2008.htm Apple trees take 5 or so years to grow. I've got some nice varieties from local nurseries that are really big, and they produced sooner. Another strategy is to wait till fall and get the cheep big ones from your local nurserymen, They plant fine in the fall too. Then graft your variety on them later. Apples from seed don't work so good as they tend to rarely produce sweet offspring.
Pear -- similar to apples. Cheap in nurseries during fall, heirloom varieties are good too.
Cherry -- super easy to grow, you can start from seed, but it will be longer. There's sweet cherries and pie cherries.
American Persimmon -- very tasty fruit, few people know what they are. Fruits stay on tree till mid winter and are a good sweet fall treat. Seeds grow very well.
Paw Paw -- notoriously hard to grow, but very tasty banana like fruits. Can be grown from seed.
Mulberries -- These guys are very hearty. Learn to identify them and pull them from a friends yard and transplant. There's absolutely no reason to buy them.
Nuts -- English walnut, almond, chest nut, heartnut, butternut, hazelnut, korean nut pine, and if usda predictions are right pecan will soon be good for my zone too. Nut trees are going to take 12 or more years. Try not to move to some other place. Acorns, hickory, and black walnuts are way too common for me to desire planting them.
Suggestions on where to buy
Oikos tree crops? I like these guys. Their variety is Great and their philosophy is good too. Sometimes they are the only ones with the tree I want. They had a great special on Korean nut pines a couple years ago.
http://www.nafex.org/links.php Here's the link page for the North American Fruit Explorers. These guys are where to find the heirloom fruit and nuts trees of old. Their list of suppliers is a great one!
Arbor Day foundation arbor day sounds like some kind of charity, however I don't think it is. It's more like a Sams club for trees. They have very inexpensive trees and a fair variety, although I don't think I would put them in my will or donate. I've bought plenty from them and I have been a member because the discount was worth it.
Perennial fruit and vegetables
Asparagus – This perennial plant will grow back year after year in the same spot for over 20 years. I suggest planting a variety of types although my favorite is purple passion. I found some deals on craigslist from some growers who ordered in bulk. You could also transplant some roots from the ditches in spring. (They grow wild everywhere in IL)
Bed preparation and weeding will have to happen for the first year or so, but then you just pick until june. My chickens liked to eat the young stocks so I had to put fencing over them.
I started this 80 root bed two years ago and this spring I plan to harvest enough to start canning and freezing for winter. My road has a ton of wild, but nobody is gonna drive by and pick out of my yard.
You can see I mulched this guy for weeds.
Strawberries – Strawberry beds continue to expand and grow with shoots that root themselves. Eventually they thicken up to push out all the grass and then it’s only an occasional weed or two. You can get 100 roots as cheap $26. Think of it as 5 strawberry baskets that you buy at the store that continuously re-fill every year. It's actually more like 8-12 or so baskets but at a grocery store you could only buy around 5 with $26.
There are sweet strawberries and there are tart strawberries for jams. So you may want to grow two beds.http://www.gurneys.com/category/strawberry-plants You get 25 plants for $13. If you buy $50 worth of plants you get $25 free. So I'd get 4 plant offers wich would end up costing $26 and consist of 100 strawberry plants. My advice is to go for the June berring sweet ones. I've found the everbearers not to be as productive. My June bearing plot is early, middle, and late season june bearing and it works very good.
Sweet ones on the left, tart on the right. I'd pick every 3 days for about 2 1/2 weeks and get a lot!
Rhubarb – I’ve seen these plants grow forever. Just get some roots and put em in, you’ll have it forever.
Grapes -- I’ve got grapes growing up my pergola and plan to have a shady grape arbor on my front deck. They'll take about 4 years. You can start yours from cuttings.
This is a rooted piece of grape vine I stuck in a cup in march. It's now 9 ft tall almost to the top of my pergola. I'll do a graft/cutting post in march.
Raspberries – some of the red types produce a double crop. You can get these to grow easy from transplants. Just find some at a friends or neighbors. I don’t plant the black types because they grow everywhere all over my farm. I’ve got some huge patches.
Here's a blackberry patch. These ones produce second year vines. The black raspberries grow next to the woods. They like a transition area.
What I'm currently planning on
Aronia -- had some aronia infused apple cider this year. It made it taste really good. My neighbor has a tree and I've put some seed in my earth tainers to sprout.
Saskatoon -- I've tried blueberries and failed, but Saskatoons are like big blueberry bushes. My neighbor also has some with young sucker shoots I can transplant.
Cornealian cherries -- Kind of like big red sour cherry trees. Also plan on transplanting a few from neighbor.
Otherwise, I've got tons of seed put in dirt containers for transplants. I'll be ordering root-stocks for grafting at school and I've already got plenty of fruit trees in the main yard.