Congratulations on your bargain! I used to have a brilliant orchid collection - I think I had about 40 at its height. Mostly Phalaenopsis but several other species too. It was in London where I had several long, deep north facing windowsills, which they loved. Most were rescue plants, due to be thrown out by my employers (I was an office plant waterer for a while) which I smuggled home and nursed back to flowering.
Then while I was doing an internship at Kew, they held an orchid extravaganza in one of the glasshouses, and at the end of it sold off all the orchids to staff at crazy prices. I bought about half a dozen. Sadly, they were infected with supercharged mealy bugs which spread to my entire collection, and proved to be resistant to every chemical available. I should have known - the glasshouses at Kew are infested with all sorts of pests, which have built up resistance to such an extent that they'd probably survive a nuclear holocaust. The cockroaches in there are gigantic.
Pretty much my entire collection was wiped out. I left London with just two survivors - a pearl orchid (currently flowering
) and a special yellow Phal. I've since been bought a couple more as gifts, so I have a few dotted around here, but I've lost my appetite for orchids a bit after that experience.
They key to happy orchids is plenty of light but not direct sun (north facing windowsills ideal), clear pots so the roots can get light, water regularly but allow it to drain - the roots must never sit in water. After flowering, cut back the flowering stem about a third to a half way down, just above a node. Don't repot - they like to be pot bound with roots flowing out messily.