Some advice on buying orchids please?

[iammadeofdreams]

Since I only have one orchid right now, I have decided that he is lonely and must have a friend (or several). Also, it just so happens that there is a home & garden show in town this weekend; which to me sounds like a perfect excuse to find a friend for Floyd since the local orchid society will have a table there.

The thing is, I have no experience buying orchids outside of grocery stores. I have done a ton of research on here and other websites, and I'm sure the OS people will be helpful, but I am still kind of nervous about it all. Other than checking for healthy roots I'm not sure what to look for or what to ask to make sure I get a good plant that will work out well for me.