The wise old farmer method
So this is how I learned to grow potatoes.
I was working in a hospital ward, and at visiting time I noticed a man in a checked shirt visiting his dad. His shirt made me think (rightly!) that he was a farmer, so I went to say hallo (because I'm nosy, and you can learn an awful lot from farmers!). It turned out that he was a commercial potato farmer, so I started picking his brain for tips on how to grow my own potatoes. Suddenly, his dad and a man in the bed opposite got very involved in this conversation, both being potato-growing enthusiasts themselves, and they had some fantastic pearls of wisdom to share with me!
I was urged in no uncertain terms to put my seed potatoes in pots, covered in soil, "under the bed". This threw me, but apparently "under the bed", the one you sleep in, in your bedroom is the perfect place to get things going (dark enough and warm enough). When you see a green shoot no more than one inch high, cover it with more soil and carry on like that until it's safe to plant them outdoors. By safe, I mean after the last frost - so a bit of a guessing game!
Once planted 12 inches apart in trenches, keep covering any green shoots with soil until you see a shoot with a flower on it. After that, just let them grow. Lots of foliage shoots up from there on in, and all you have to do is wait for the flowers to die and the foliage to kind of wilt. Then wait a week or two more.
So after 5 months or so, having followed the advice of my lovely hospital patients I did an exploratory delve beneath one of my potato plants and found plenty of nice-sized potatoes. Thus encouraged, I went for it and had a fantastic crop of huge Marfonas and excellent Pentland Javelins - 20kg all told. So give it a try - it's actually quite easy and very rewarding!