there are lots of medicinal and culinary herbs you can grow with a small amount of space. cherry tomatoes as hobbes mentioned are also great. hot peppers or banana peppers are good. green onion or chives.

even viney/crawling veggies can be done with trellises. but its good to start off simple with mainstay varieties and as your thumb gets greener, get more ambitious.

personally i would focus on what exactly you want to grow first, a lot can be accomplished with some ingenuity. for instance, pallet gardens are ideal for small areas. there is a wealth of knowledge on the web with regards to this topic.

i grow quite a lot at my place, over 50 varieties of herbs and veggies.