If they are Standard Cymbidiums, they may never bloom as indoor plants. I am sure Australis has his ideas as well.
But Cymbidiums do best grow outdoors for as much as possible. You gradually move them outside in the spring once all dangers of a 'hard frost' have passed. They like it on the cool side, say temperatures from the upper 40's through low 80's. They do not enjoy too much warmth.
You water them well while growing outside. Fertilize every 10 days to two weeks, at a tsp. of water soluble fertilizer in a gallon of water.
Never let them get too dry. Then in the fall make sure they get 2 weeks of cool night time temperatures averaging in the low to mid 40's. They can even withstand a little light frost. Once you have them chilled a bit, you can bring them inside in a bright area that gets a little sun. After 4-6 weeks you should definitely see bloom spikes coming up.
Chinese Cymbidiums with cascading flower spikes of starry flowers do not like it quite that cold. But in my experience they like a cool place too grow. They are not what we would call warmth tolerant orchids.
Without cooler conditions you may never see flowers but if you chill them you should see 10-20 blooms per spike.
Outdoors it is 4 hours of sun, lots of water, lots of food and not too warm.
