I have saved those tubers as well and am going to plant them right outside in the ground in mid May. From what I gather you can get the roots started in water but folks report varying success with that. Yes, potatoes are very easy to grow. Plant the seed potatoes in early May in shallow trenches and continue to mound soil up around the plants as they grow all summer. By fall you will have mounds instead of the trenches you started with. After frost kills the leaves, dig up your buried treasure. You usually get 5 lbs. of potatoes for every pound you planted.