Get some orchid potting medium and a pot and then pull the whole thing out of it’s current pot. Knock off all all the old medium. Take a pair of scissors and cut off that limp leaf, as well as any roots that are soggy, soft, or gray – keep just the firm, green ones. Then put some medium in the bottom of the pot, set the plant down in it, and pack medium around it tightly enough to secure the plant (don’t treat it like a sissy, go ahead and pack that stuff down). Water it thoroughly (hold it under the faucet or dunk it in a bucket of water), let it drain, and then set it near but not directly in some nice, bright light. Water it every 1–2 weeks. You can use orchid fertilizer in the water, but I usually don’t. Mine bloom 1–2 times per year, usually in the winter. When the bloom spike comes up, you may want to stake it to keep if from drooping over. After it finishes blooming, cut the spike back to just above the last flower node and wait a while – it may rebloom from that same spike. If the spike turns brown and dry, go ahead and cut it off near the base and wait for the next bloom cycle.
Really, i just ignore mine in their sunny spot for most of the year, and bring them in and set them around the house when they’re in bloom. (I do water them more often while in bloom, it seems to keep the flowers around longer.) If you’re in an area without deer, you can even set them outside in some shade and forget them for the summer (just spray them with some water in dry periods).