Do nothing yet
Around about the beginning of March put them in trays in the greenhouse with some compost and start watering-that and the natural warmth will start them into growth
You will then see the eyes and that is when you can split them or allow them to grow a bit to take cuttings
The thing you are aiming for is healthy plants to set out from May onwards depending on your last frost date-this may be as late as the end of May.