To 'chit' your potatoes simply place the seed potato with their 'eyes' facing upwards in egg boxes or trays in a warm, light place so the short green 'chits' appear. Once the chits are 5-10mm long the potatoes are ready to be planted out into either the ground or your chosen container.
I'll be off to the Skelmersdale Potato Day this weekend to get my seed potatoes but looking around locally a lot of places are doing a really good price on seed potatoes including Wilkinsons who also have a wide selection and some pound shops have them in already too.