A Dtps is a Doritaenopsis, which is a member of the phalaenopsis family. Follow these rules and you will be fine!
1. Phals like medium to high light - east or west window is best. South window is okay if it is shaded or has a sheer curtain.
2. Watering: Your dtps probably has some sphagnum moss or bark as the media, and with this type of media, it is critical that you allow the plant to dry out in between waterings. I would say no more than 1x per week at most. Most new orchid growers overwater their orchids, so don't do more than this. Its just for safety.
3. If you have a small fan, keep the air moving around your orchid w/ it. Since they come from a jungle, they do like good air movement, and this will also help your media to dry out more quickly and prevent any kind of rot.
4. Fertilizer: Feeding your orchid is important, since the dtps cannot get nutrients from the media it is grown in. Put a small amount of fertilzer into the water you use to water (think less than 1/4 tablespoon per gallon) and it will keep your dtps happy.
5. Humidity: orchids generally like high humidity, but for phals, anything about 50% is fine.
A Doritaenopsis is a epiphytic orchid, which means that it grows on trees and NOT in soil. As such, remember that orchids are very easily overwatered - they are not meant to have water on their roots constantly. Think about how the grow in the jungle...they afix themselves to the trunks and branches of trees in jungles, and their roots hang freely to capture humidity from the air...they were never intended to be in pots, but we do this for our own convenience
So, be careful, lean towards underwatering as opposed to overwatering, and don't move it around too much, you'll do great! ~Becky