I keep them under HID light over the winter. I cut back on watering and don't fertilize at all, though they don't get fed often during the growing season either. They do well and some varieties will continue to bloom sporatically throughout the season. Just keep and eye out for insect infestations, especially spider mites, mealy bugs and scale.
Karyn

I have mine in 5 gal pots sitting in front of a south facing window (or as close as I can). Spider mites are a big enough problem in winter to warrant using a systemic.

~Chills