I know of several folks who do not have a "yard" per se, yet have successfully grown greens in those whiskey barrels, just one or two on their patio, and grew enough to get a salad out of it every day. I don't know if there are bad chemicals in those barrels, though, so you might want to use another type of large pot. But the point is that you don't have to have a huge yard to grow some healthy foods, which are costing more every month as more and more people flock to the healthier lifestyle. Here are some things we are growing this winter (we live in Texas so have already started, in spite of the pesky armadillos digging everything up looking for grubs), and you can, too:

lettuces (these are MANY different kinds, choose ones for your climate/soil)
chard
kale
collards (yum, slathered in bacon drippin's!)
beets (the tops are extremely good for us)
kohlrabi (again, good for the tops although the bottom's not too bad)
turnips (disclaimer: kids absolutely won't eat)

These alone provide us with most of the greens we would otherwise buy at the store at a cost of 2-3 bucks a bunch. Plus eating from your garden is just being so much fresher. We haven't harvested yet, but the beauty of these veggies is that you can cut a leaf or two from the plant, and they grow more for you to cut in a week or two. We still have two chard plants that survived our hellish Texas summer, and are now thriving in the cooler weather.

Top tips for success I wish someone had told me: pick varieties suited to your climate and soil, and plant several varieties to keep it from being boring, we all get sick of eating the same type of lettuce in our salads. With the vast array of varieties out there, no need to get bored.

The bulk of garden work is getting planting everything, after that, it's just maintenance, which includes harvesting. Nearly every county extension agency has a website and phone line for help, and the 4-Hers are good resources as well.