Many people by these wonderful bulbs year after year, but a potted Amaryllis will live and flower for many years if looked after properly, caring for it by following the natural cycle of the plant.
For a Christmas flowering Amaryllis, In October or November you should place the pot in a light warm place (20 centigrade is good) and water it a little and often until the buds appear.
Increase the volume of watering gradually as the shoots grow and enjoy the wonderful flowers.
The important bit is to continue watering once the flowers have faded.This usually happens in January or February. Cut off the flower stems and continue to water your Amaryllis till July, feeding with an organic general purpose plant feed every 2 to 3 weeks.
In July you will want to stop watering altogether, allowing the plant to go dry. Store the pot in a cool place such as a garage until early October when you can begin the whole process again, leading up to a second christmas flowering. If you follow this advice the Amaryllis bulb will continue growing for many years to come.