What to use for containers...depends on what the good Lord provides. Things I have used....5 gallon buckets, old wood boxes, plastic cement mixing containers, kiddie swimming pools, containers from the dollar store that hold about 6-7 gallons and have plastic rope handles. I wouldn't use gallon jugs myself as they would dry out so fast in the heat of summer unless you set up a drip system or the like. For planting medium I often fill the bottom with horse manure of any age and then add planting mix with added compost. The horse manure rots down and may even provide some heat plus it saves on the need for so much "good dirt". Of course you could put pretty much anything in the bottom of a deep container since few root grow that deep.
I plant just about anything in containers, peppers, beans, tomatoes etc. In a shallow container, like a plastic kiddie pool, I'd do lettuce, radishes onions etc. In fact I usually have one of those going most of year with Remay over it for frost and deer protection with something in it. A buckt of herbs is nice too cos you can bring it in when frost threatens and have fresh herbs later in the fall.
Use your imagination and have fun!
Liz