What about humidity? It's incredibly dry here and that's what makes my nervous about keeping orchids.
Some of the common windowsill orchids that you see at Home Depot or wherever are among the easiest and most forgiving of houseplants. There are some kinds that do just fine in pretty dry air. Most orchids live up in the tops of trees, so they have to be able to survive dry conditions. The most important consideration for most orchids is that they need very good drainage. Most are also intolerant of salts, so it is best to use rainwater or RO.
I have a few orchids going right now. Here is a shot with a little Phalanopsis hybrid and a Sophrolaelicattleya (a tri-generic cross) on top of the fridge.
Putting several plants together like this is another good way to increase humidity in their microclimate.