Spring Lettuce (click here to see how much it's grown)
Heirloom variety tomatoes - determinates are perfect for small space gardening
Homegrown lettuce is truly the gift that keeps on giving. I've thinned several gallon sized containers from the lettuce pictured above over the last few weeks by cutting the large outer leaves and allowing the smaller ones room to grow - now you can't even tell we've pruned any. The texture and flavor of homegrown lettuce is incomparable to that of anything store bought (organic or not).
Besides some herbs and lettuce, I've also started some organic heirloom variety tomatoes which are determinates. This is key because most tomato varieties are indeterminate, which means they basically don't stop growing until they are ready to die. I don't have space for that. However, these determinate varieties will grow to a certain height (usually about 3-4 ft) and then they don't get any taller - perfect for a small space garden like the patio my family is confined to for the time being.
Trust me, no matter how small the space you have is, chances are you can grow your own herbs and some basic vegetables with very little challenge. Start with good soil, ensure you have good drainage, then water on a schedule and you'll be all set.