There are a variety of plants that grow from bulbs or tubers that are not winter hardy and must be dug up each fall and stored indoors for the winter. This group includes gladiolus, dahlias, cannas and calla lilies. Im using the term bulb here loosely to include all the various storage parts of these plants because to be accurate Id have to call some of them corms, some rhizomes, some tubers, etc.
Wait until a light frost has browned up most of the foliage then dug up the clumps and let them dry for a couple of days on newspaper in a sheltered location. Shake off the excess soil and cut off the tops of the plants a couple of inches above the bulb or tuber.
To store them over winter I have the best luck using a paper bag with peat moss or dry sawdust. The basement is a good location, just watch out for hungry mice.