My MIL always laid the tubers on their sides and started them in the house in swallow alluminum pans with damp (not wet) peat moss. Once they sprouted and got 3 inches tall, she would plant them in her large terracotta pots where they stayed for the summer.
In the fall, after the first frost, she would pull the pots in the garage and wait for them to dry out and dig out the tubers and store them in a plastic bag with more peat moss. I believe she used the same tubers, and production of more from them, for nearly 20 years. I've been doing the same process now for my FIL since she died 12 years ago - but he won't give up the tubers. Maybe, eventually, I'll inherit them.
-Laurie