Also, grow what you like to eat! It's no use planting lots of courgettes if you hate the things!!!
I'd start with things that are fairly expensive to buy in the shops (I love runner beans, but won't pay the extortionate prices demanded by supermarkets). I find these will grow quite happily in my garden.
Is it worth buying a few fruit trees to try and shelter the plot, whilst at the same time giving (eventually) a crop, or is the plot too exposed for trees to thrive?
One bit of advice that I've found invaluable, is not to plant root crops in freshly manured plots. If they grcan find the nutrients they need in the top level of soil, they won't grow decent sized tap roots.
A good book is also a good idea (especially at this time of year), I bought John Harrison's Veg Growing Month-by-Month, and it's been really useful. You can buy it fairly cheaply on Amazon, and it's a great place to start, it has lots of ideas and do's and don'ts in there, brilliant for the first time veg grower.