There are many orchids under the name dendrobium with diverse needs. You’ll want to start here and adjust your care to your specific plant’s needs.
These are medium light orchids, putting out long stalks with a dozen or so one to two inch flowers. I like the bamboo like, oriental look they have even when they are not in bloom. Many dendrobiums go through a winter dormant time. I find mine don’t grow during this period.
Dendrobiums are happy in an east or west window, too much sun burns the leaves. If you do put them outdoors put them in the shade.
Dendrobiums like warm temperatures, between 65-95’F, warmer temperatures encourage kikis (babies) to form on the stem. A temperature difference of about 15’F daily and cooler temperatures are needed for blooming. Sitting them on a drafty windowsill is usually enough. Otherwise you may want to summer your plants outside in the summer. Mine bloom in the winter, I live in Houston.
I find mine do well planted in clear glass with bark, or better planted with clay pellets ( semi-hydro ). If you go with semi-hydro your water quality will have a strong effect on how well your plants do and don’t forget they need the micro-nutrients in the fertilizer as well as the main nitrogen, phosphorus and potassium.
They like to be root bound, so re-pot them only after the roots climb out of the pot. Roots should be green to white in color, the greener the better.
The more humid the better, drafty windows work, terrariums if they are not near a window, or spraying the leaves with water a couple times a day if the house is dry. 50%-80% is best.
The stems will get deep groves in them if they have been under watered for too long. Water them just enough to keep the stems from getting groves. Do not leave them sitting in water.
In the winter water your dendrobiums less, Dendrobium nobiles will drop their leaves after flowering or heading into the winter. As long as the main stalk feels hard not soft don’t worry about it. New shoots will appear in the spring.