Steph A.- I wrote a long reply to your question in the comments section, but on the off chance that anyone else may have similar questions I decided just to post the reponse here instead.
Q. I've got a really small space to start a garden. What should I grow?
A. Really you could go for just about anything. It's just a matter of what you really want to eat/grow. Tomatoes would definitely work. You could try 2 different tomato types with some basil planted in between. They grow well next to each other and are good to eat together too. You could also do peppers or eggplant or beans- but tomatoes are my favorite so I would always recommend them first. If you only have limited space pick something that you know you'll be excited to eat (be it lettuce, watermelon, tomatoes, etc) as that'll give you motivation to stick with it.
Q. Should I start plants from seeds or buy the already established seedlings?
A. As far as starting with seeds vs. plants. I would suggest that for most things just stick with buying the already started plants. Unless there is a very specific variety that you want that is only available as a seed, I'd say start out with the plants as they are much more reliable and easier to get going. However, I'd recommend against using the seedings available at the big hardware stores. They can be pretty unhealthy, and they may only have one variety to choose from. My advice would be to check out the West Chester/Phoenixville farmers market in may/june. I remember that there are a couple of vendors there that sell really great, healthy tomato seedlings that are ready for planting right away. Also, these are from local growers so they are types that are choosen to thrive in our local growing conditions/climate.
Q. Should I try growing stuff in pots?
A. I would totally recommend growing stuff in pots. You really can grow anything in containers that you grow in the garden so, again, it's totally just a matter of what you are into. Plants like tomatoes, and peppers work great. Or you could do an 'cooking herb' pot, with oregano, thyme, rosmary, chives etc. Or a 'salad pot' where you get a couple of different types of lettuce and plant them together. Herbs are another thing that I'd recommend buying as seedlings at the Farmer's Market. If you do want to buy seeds (lettuce and salad greens are something I would recommend growing from seed) I'd again skip the hardware store and go to a garden/ farm supply store. I used to go the West Chester Agway- it's right near Kelly's Sports. They have a way better seed selection then Home Depot or Lowes. Lastly if you google "container gardening" you'll find as much information about the specifics of this as you'll ever need.
My basic advice: Keep it simple. You'll have a better chance of being successful, and you'll be more likely to try some new things the next time around. I hope this helps!