Raised beds are the way to go for me. Check out the book Square Foot Gardening. It is amazing how much you can do with so little! You do not need more than 5 inches for anything except potatoes. Those can be done in less than a foot... and done very well. If you want potato ideas, youtube has an awesome selection of different ways to grow them. The 'mels mix' soil from the book is great for growing and retains moisture like a champ. The beds allow almost no weeds. Water 2-3 times a week and call it good.