Either growbags or pots would be fine, make sure if you go for pots they are a decent size, apart from that you will need to water often (probably twice a day in the middle of summer if the sun actually shines) and feed the plants when they are growing (bought liquid feed in with the water). I'd probably start with herbs and salads, not so much to sow now, mostly winter lettuce, mizuna, pak choi, mustard greens etc. But loads of stuff will do well - including toms, chillies etc esp if you are in a town/city it is often warmer than out in the country . . .
We've got a copy of Vegetables from Small Gardens by Joy Larckom - I think its been replaced by Grow Your Own Vegetables which is aimed at any size garden, but you might be able to come by it 2nd hand. It was a godsend in our days of having a 6ft square patch carved out of a shared back garden.