Eating food farmed locally reduces environmental impacts, and it doesn't get more local or fresher than growing your own at home.
Anyone with a pot and a sunny spot can grow herbs, and even vegetables. Not only does growing your own save you money, it's been shown to increase intake of fresh greens and lower obesity rates.
Herbs are very hardy and a great option for first-time urban farmers. Some easy options include: basil, rosemary, oregano, mint, thyme. Generally speaking, herbs originate from sunny mediterranean climes and so they like a lot of sun. Keep them well-watered, but not water-logged; the soil should be moist.
As for vegetables, nearly all can be grown successfully in containers.Try several: spring onions, mustard greens and dwarf tomatoes, for example. See which thrive and which fail in the specific microclimate of your balcony or windowsill. Don't eat your crops too energetically at first -- give them a chance to get established and then nibble from alternate plants.
It's satisfying and cheaper to buy and grow from seeds, but novice container gardeners may like to get their plants already formed from the nursery - that counts too if you can get them to grow! Later on you can propagate new plants from shoots of the extant ones.
(Olivia Rose-Innes, Health24, November 2011)