Check out the wintersowing forum for how to sow seeds in recycled containers, and there is also a list of the plants that grow well in your area. You could also check out your county Master Gardener office for material and classes. For your first year I'd recommend keeping it simple.

5 gallon plastic buckets or litter buckets (with 4-5 holes in the bottom) work great for inexpensive containers. Check out Freecycle for "free" containers. Fill the bottom 1/4 with empty plastic bottles or beverage cans so you aren't wasting expensive potting mix on the bottom of your containers. A 5 gallon bucket will hold 1 tomato plant or 2 peppers.

If your budget doesn't afford buying plants start from seeds, you can save the seeds for next year and save money.

My recommendation would be to put your money in good soil-less potting mix like Promix, do not use a mix with water crystals in it for any plant you plan on eating. Buy the 3+ cubic foot bag, it's about $40-50 but should many containers. Moisten the mix in the bag before filling containers because the peat moss is difficult to moisten afterwards. Pour water into the bag and stir, keep doing this until every piece of peat moss is moist, then let it set over night. Fill your containers and plant.

My advice is to not overwhelm yourself and enjoy gardening.

I also live in the Lancaster area. Because of your limited space, I would suggest you narrow your focus to what will give you the most pleasure.

Do you like color? Do you enjoy cooking with herbs? Do you want to eat home grown vegetables?

The most important part of gardening is the soil, whether it is in a pot, or in the ground.

If you want to enjoy color for the longest period of time, then pot up various annuals.

i personally have not had success with container gardening because I lack the discipline to water the pots regularly, and then the plants die. I've also learned that containers can not be in direct sun for long periods of time, which eliminates most of my back yard. So I can't be very helpful with suggestions for successful plants.

i would definitely recommend buying plants instead of starting from seed, because seeds need to be started indoors about this time of year and can take up a lot of space indoors.

Also, Lancaster county has a large selection of vendors who sell greenhouse plants. Any plants you find at these establishments will grow well here. You could visit Stauffer's of Kissel Hill at Rohrerstown, Oregon Pike, or Lititz. My favorite for low cost plants is the Flower Wagon on Lexington Rd. west of Lititz. Both of these establishments have vegetables, annuals, herbs, and perennials.