Make sure the pot has drainage holes. You can't properly water an orchid unless it has holes through which the water can drain. Water sitting in the pot will cause the roots to rot, so it needs to be able to drain through the bottom. If you bought an orchid that came in an ornamental pot without holes, repot the orchid in one with adequate holes in the bottom. Use an orchid potting mix instead of regular potting soil.
Some orchids have water-storing organs, and some do not. If you have a type of orchid that has the ability to store water, such as cattleyas or oncidiums, you should allow the orchid to completely dry out before watering. If you have a type of orchid that does not have water-storing organs, such as phalaenopsis or paphiopedilums, you should water the orchid before it is entirely dry.
Once you develop more than a passing interest in orchids, you will quickly notice how diverse this exotic plant family is. Encompassing genera that yield both the vanilla you love to bake with and fragrances you love to wear, each flower has unique characteristics and care requirements. Compare your plants to some of the most commonly cultivated orchids to help you determine what type of orchid you are growing.