Potatoes can be planted at any time of year, provided you keep them free from frost. If you have a polytunnel or greenhouse then you can plant them in December or January and have very early potatoes on the table in March and April (early varieties take around 80 to 100 days before they are ready.
If you have enough space, the seed potatoes can be planted in beds, just as you would outside. Another way to grow them is in large containers or grow bags. Filled with good quality potting compost and and a general purpose organic feed (such as Greenvale). The grow bags can be topped up with compost in stages as the shoots lengthen.
Potatoes are sensitive to frost. So if the weather looks like getting well below freezing, you should either apply a little heat to your tunnel or greenhouse to keep it above zero, or cover your young plants with crop cover.
Make sure to irrigate the plants as they grow. One advantage of planting this early is that you can be pretty sure not to get blight on the crop.
When the plants are looking mature and they've been growing for between 80 and 100 days, have a look to see how the crop is doing and you should be ready to harvest some delicious early potatoes.