Purchase a healthy orchid that adapts well to indoor conditions. Good beginner orchids are Paphiopedilum, Phalaenopsis and Cattleya.
Place the orchid in a location where it gets bright indirect light. Low-light orchids like Phalaenopsis and Paphiopedilum like a location near an east window or about 2 feet away from a southern window. Higher light orchids such as Cattleyas like a bright east or west window or slightly shaded southern exposure. Be sure that none of your orchids are in the direct sun although high-light orchids such as Vandas could use morning sun in the winter.
Protect the orchid from sudden cold drafts and temperatures below 55 to 60 degrees Fahrenheit. Ideally the temperature should be about 60 degrees at night and about 15 degrees warmer during the day, with a humidity level above 40 to 50 percent. Some orchids such as Phalaenopsis prefer it to be a little warmer, at about 65 degrees at night.
Water the orchid about once a week, more when it is warm out. Orchids such as Cattleyas like to dry between waterings. Paphiopedilums and Phalaenopsis should remain moist but not wet. Dendrobiums like to dry out a bit in the winter when they are not actively growing, but need to be watered more when they are producing new roots and canes. When watering, thoroughly saturate the potting medium by using enough water to equal twice the pot's volume. Let it all drain out of the bottom.
Fertilize with a water-soluble orchid fertilizer once a month while the plant is actively growing.