Like Poinsettias and Christmas cactus, Kalanchoe are common in floral shops In December and make an excellent seasonal gift. They are one of the few plants that can be made to bloom indoors in the middle of winter (poinsettia's red 'flowers' are actually modified leaves, called bracts), and they are tough as nails, to boot. Most people leave Kalanchoe on their windowsill for a month or so until the flowers fade and then throw them in the trash—which is a pity, because they are actually a perennial species and will bloom again and again with just a bit of care.
Kalanchoe are a type of succulent from arid regions in Madagascar, so the first key to keeping them going is to not overwater. Let the soil dry out fully before watering, and don't let them sit in a drainage pan full of water. They are a tropical plant, so it's imperative to keep them above 50 degrees at all times—in late spring you can put your potted Kalanchoe out on the patio in a sunny or partly sunny location, just be sure to bring it back indoors well before the first frost of fall.
The plants should bloom again when you put them outside in spring, but you can coerce them to bloom the following winter, just like the nurserymen do. Kalanchoe are naturally spring-blooming plants, but because they are a tropical species, it's not the shift from cold to warm that triggers blooming, it's a shift from slightly shorter days to slightly longer days. All you have to do is mimic this shift in day length. Starting in mid-October, subject the plant to 14 hours of total darkness (put it in a closet or place a bucket over it) and 10 hours of bright sun each day. Water minimally, during this period. Within six weeks, new flower buds should be apparent and you can leave the plants in your windowsill for the rest of winter.