I don't really do resolutions per se (this post by Meg Barker is excellent on the matter). But if you looked out, on a bright, sunny New Year morning, at your patio (or balcony, or windowbox...) and thought about growing food in it, you needn't put the whole thing off til spring. Sure, it's not the time of year (in the Northern hemisphere) for doing much planting, but there are still things you can get started on now.
First up is planning. If it gets to March or April and you haven't given any thought to what you'd like to grow, that's fine (it's better to throw a few random seeds in than to do nothing), but even a little thought in advance can make your space much more productive. What veggies do you most like? No point in growing things you won't actually eat. How much space have you got? Do you need to find some containers? Can you order seeds now? The Real Seed Company are good for seeds (and browsing their website may give you ideas), and nearly anything you can put some drainage holes in the bottom of can become a planting container.
This is also a good time for planting fruit. Blackberry, raspberry, blueberry, blackcurrant, and the rest will all grow happily in pots. Blueberry in particular may be better off in a pot, as it is ericaceous (lime-hating) and needs specific compost or acidic soil. (If you already have a blueberry, in fact, now is a good time to pH test the soil, and add compost, or water with 1-2 tbsp of vinegar in a gallon of water, if needed.) You can buy bare-root plants and get them in the ground over winter, though you're unlikely to get a crop until summer 2014. I confess I've never personally managed to make blackberries or raspberries work in pots, but I am assured that it is possible. Perhaps I needed a bigger pot.
You could also consider a fruit tree (an apple, perhaps), if you have space and ground. Fruit trees too can be grown in (large) pots; I have a satsuma tree in a pot, but it's not doing so well. Down at Downing Road Moorings, near me, they have a lot more success with trees in containers (of sorts). If you already have fruit trees or bushes, now is a good time to prune. You usually want to lose about 15% of old growth each winter.
Finally, it's never too cold and dark to try planting a tray of microgreens. Get sme rocket or any other green-leaf seed (mizuna is nice), plant it in a shallow tray on the windowsill, and wait until the second set of leaves (the first set of "real" leaves) appear. Harvest with scissors and eat.
See my book for more detail on any of the above, and ideas for getting going with permaculture container gardening whatever time of year it is. And watch this space for an update on my own plans for my garden this season; I'm planning to sit down with a notebook this weekend.