I know it's becoming kind of a faddish thing, but 'tis the season for planting and growing. You don't have to truly have a green thumb to be a successful vegetable gardener. You don't have to put in expensive planters and buy $200 worth of Scott's garden soil. Try a bucket, or pot, or big ice cream tub. Find a big container that has some drainage, or bust a few holes in the bottom, fill it with dirt, and plant away.
I'm a messy and very scattered gardener. I randomly plant things a few at a time, and quite often forget to water or weed, and even I'm successful. Here is what we have growing right now...
Moby grape tomatoes
Green leaf lettuce
Red leaf lettuce
Keep in mind that herbs and leaf lettuce can grow in a smaller pot in your windowsill all year long. Fresh herbs are expensive, but they do add a lot of flavor. Buy a packet of seeds for 99 cents, plant a little every couple of weeks, and you can have fresh herbs all year long. Keep it simple and start small, and you'll be surprised how much money you can save and how exciting it is to grow something yourself.