First off orchids should never be kept in "Soil". Not even terestrials orchids should be in "Soil" Cymbidiums can grow in a heavy soil mix and take the wetter conditions but still not recomended.
Ok all rescue plants need repotting period. You have to inspect the root system and remove anything rotten. Firm roots are ok but like someone else said white are excelent roots. The green tips come when the root is growing. Get fresh orchid bark. Can use the stuff from lowes or wally world but stay away fromt he peat based phal mix. I don't recommend it.
Remember orchids are epiphytes and grow on trees in the wild. So they getr watered every day with the dew and dry by night. So we make them adapt a lil by only watering a few times a week and grow in a pot. Now when you go to repot the medium should be soked over night before potted up. Make sure there are good drainage holes in the bottom and sometimes sides of the pot. (Orchids are sold to "Look" good not grow at the chain stores.) So Now you have it repotted and you want it to recover. Sarahlydear told you a great method to see if it is time to water. I recommend the same thing but use a bamboo screwer instead. If it comes out damp wait a day. You want it to come out dry but not bone dry. Also when you water YOU WATER!! Flush the pot. Orchids are very sensitive to accumulated salts. So water the crap out of it. you CANNOT over water with your amount of water at one time. You over water by watering too frequesntly and keeping the plant too wet. I water plants atleast every other day during the summer here in GA and SC. Sometimes every day. and with fresh media you can do that. As the medea decays it holds more water. That is where learning how to grow comes in. Remember orchdis SHOULD be repoted once a year to keep the medea fresh and the air pockets in the bark.
Fertilize weekly weakly That is 1/4 what the package says once a week. Do this once you see new roots coming. You will notice the roots turn green if when you water if the plant is thursty.
Phals bloom once a year. They can be enticed to rebloom lower on the spike but keep in mind it keeps the plant from devoting energy to recovering and growing. Once they have a good year of growing the cooler temps cause it to spike. Temps of 50 F for 3 days and it will trigger a spike. A few months later you have flowers.
Keep water out of the crown like someone else said because phals are prone to crown rot.
Orchdis are rather easy. They are just different. And have specific needs. The book All about orchids by ortho is a great book. Lowes has it for around 18 bucsk. Atleast it was. Phals can take it wetter than alot of orchids and also have the longer lasting flowers too. If there is not too much change in the humidity while it is in flower then they last. WHen I bring a plant in from the GH the change in humidity shortens the life of the flowers, but the plants grow better when outside. So it is a trade off to me.
Try to stay away from sphag with phals. I know it is used alot and can be done but it breaks down too quickly and you end up loosing the air pockets. Not recommended.