My recommendation is to use the square foot gardening method. I think you can find it at www.squarefootgardening.com. It's about using a 4 foot by 4 foot box, that is only 6 inches deep. The mixture inside is peat moss, compost and vermiculite (1/3 of each). My daughter and I did this last year, and the veggies grew GREAT!
I got the book from the library. The newer version says to use boxes that 6 inches deep, the original book said 12 inches deep.
My husband built me one box that was a foot tall, and we grew carrots in it - it was awesome.
I'd recommend getting the book (hopefully your library has it). The book is a bit on the info-mercial side of things, but it can be a fast read on what to do.
The soil mixture is great - it's very light weight would work well for container gardening.
Good luck!