If you didn't do so earlier in the winter, spread well rotted manure or compost over vegetable beds and cover selected areas with cardboard, black plastic or carpet to start warming up the soil. The soil in raised beds will warm two weeks at least before open ground which will make it easier to grow in later in the spring. For those beds which are not covered or for open ground, turn over the soil if the weather is good. Keep off the beds to prevent soil compaction - use timber planks to stand on for access. If you have not already done so order/buy your seeds, spuds and onions. Chit seed potatoes – put them in a container (e.g. used egg carton or empty seed tray) and leave them in a bright warm place.
Finally, we can sow some seeds. On a sunny windowsill indoors, in a heated greenhouse or on a heating mat: sow celery, globe artichokes, celeriac, leeks, onions, lettuce, tomatoes, peas, aubergines, peppers/chilli-peppers. In polytunnel or greenhouse: beetroot, Brussels sprouts, summer and autumn cabbage, carrots, leeks, lettuce, radish. Outside: Weather permitting you can try planting out broadbeans, spinach, kohlrabi, onion and shallot sets, Jerusalem artichokes, parsnip and early pea varieties. Now is a good time to plant fruit trees and bushes. It's also a great time to start planning a herb garden - get root cuttings of perennial herbs i.e. Mint, Fennel, Thyme etc. from fellow GIYers. Buy seeds for the annual herbs like basil and coriander.
Winter cabbage and cauliflowers, Brussels sprouts, spinach, kale and leeks.