Here I sprouted a potato from last harvest. It was taken from my basement where I store them. If you buy a store bought sweet potato, there are a couple things to consider. First most are sprayed with a growth inhibitor. You will need to soak that off, and keep it warm and moist after that. Secondly you may also want to consider the variety. Organic store potatoes are recommended, however they may have an organic growth inhibitor.
Sweet potatoes make great house plants and will grow a long vine like this one. Pineapples make good houseplants too!