Check Spritzhenry's blog on growing orchids. But, briefly keep warm, not direct sunlight, do not allow to sit in water but run water through when the roots look whitish. If your water is hard you need to use rainwater to water. Feed with orchid feed about once a month. There is a new book called 'Growing Windowsill orchids' by Kew Books which is a great source of info.

Tomato feed (Tomorite) is the same as Orchid feed and 1/2 the price I found this tip in a couple of orchid books.