I've been asked about container gardening, so I'll try to give a little advice about it. I'm not the world's guru on it by any means, but I've had a little experience, frugal wise.
First, the containers. You can use anything from a beer keg to a mop bucket, but you probably want something that doesn't look too awful if you're going to have it where you'll (and your neighbors and company) will see it all summer. Think of containers you already have. Beer kegs may go in your yard very well! Five gallon buckets can be painted so they look a little classier. Large flower pots, storage containers, toy boxes or even the old bathtub will work, so make your choice. The only thing you need to remember is that a container needs drainage. If you don't poke holes in it (A bathtub has a drain hole that works fine), water will collect on the bottom and create problems for your plants. Fungi grows well in that condition and may kill the roots.
Put a layer of small rocks or crockery fragments, broken cement, etc., in the bottom of a container, then fill it with good soil mixed with compost. You can buy potting soil, but that becomes expensive, especially if you're using large pots.
A list of plants to grow in containers can be almost endless. For larger plants like tomatoes, the smaller varieties seem to do better. Almost any vegetable can be found in a compact size plant - look for those when you buy your seed or plants. Squash is hard to grow in containers, but even then, it can be done.
Things like lettuce, spinach and radishes grow very well in containers. (They'll even grow inside with enough light.)
One very good reason to container garden, besides not having enough yard space for a traditional garden, is that you can move your plants to take advantage of better locations that may change over the season, or even over a day in very hot or wet weather.
Large containers can be heavy, so think about putting the largest ones on wheels! Set them on a child's wagon or any set of old wheels you may have around.
You'll need to water much more often, probably once a day for most things, and you'll need to fertilize often, too. Natural fertilizers are much preferred in container gardening, especially. Add compost, well rotted manure, coffee grounds, etc., to the top layer of soil now and then and mix in an inch or two if you can without disturbing the plant. Remember that the plant's resources are limited by the container size and be prepared to make up for that.
Above all, experiment! Find unique containers, plant seeds you've never tried before. Keep records of what you do and learn from them for next year!