Good advice on A4a was to start at the other end - what veg do you love to eat, fresh off the plant (e.g. lettuce, sweetcorn, carrots, early spuds, purple sprahtin', baby broadies) and/or expensively (e.g. globe artichokes, aubergines, fresh tomatoes, celeriac, borlotti beans)?
If space is short, what veg will give good value per m2? I have two plots, but even so don't grow maincrop spuds - a man down the road grows and sells for £2.50 per half paper sack - or brussels sprouts - can buy those for £1/stalk at the farm shop. I'd rather have more squash and tomatoes :D
If you calculate bed or row spacing, you can work out how many of each veg - carrots etc. you might want in a typical week, and if you keep notes you'll know how to adjust for next year. Remember you'll be using some root veg from store until March, winter squash til later.
For veg varieties, ask your neighbours what they sow - with luck, they will have settled on varieties that do well in your area.
If you sow successional crops of e.g. broadies, carrots, beetroot, lettuce, chicory, Oriental veg, and cauli (All the Year Round) every two weeks from March to August, you'll have basic baby veg most of the year :)
If you want to try a few seeds, ask in the Seed Swop threads, someone is sure to have what you want ::)
if you grow what you love to eat, you won't grow far wrong ;)