I have been given a dendrobium that consists of three stalks (no leaves or flowers). The roots appear top be healthy and the stalks are promarily green (resembling bamboo shoots to some extent). What do I need to do to bring the plant to health? Is it, in fact, worth the effort? I have the information from the page devoted to orchids as house plants, but I'm not sure that my particular problem is dealth with here.

You're orchid is probably just taking a break.
Many orchids do require a resting period. This is usually in late autumn or early winter. During this resting period, they may loose their leaves, leaving only the pseudobulbs. That's ok since new growth will come from the pseudobulbs. During this stage, the plant will need very little watering, only water if the potting soil is completely dried out.
There are 2 orchid pages on this site. You probably read mine. Barb's (Flower) Orchid page seems to cover what you'll need to know. a link to my page is on the bottom of hers..