Thanks for all the replies!
I did a bit of reading in the Orchid Forums as suggested (still have much more to do). I feel I have a much better idea of (at least the basics of) how to care for one of these plants now.
I definitely think I over watered it.
If I lose the plant, it's no biggie. I definitely want to try again though and see if I can keep one of these alive long term.
I unpotted it this morning and I will post some pictures that I took. I don't have much to lose but if there are steps I can take to try to keep it alive I will.
The black (rot?) started at the center and has progressed down the leaf over the past week. I now see it climbing up the stems.
Would cutting down the stems (are they called spikes?) and trimming up the black areas in the roots help at all? Can it survive if it doesn't have at least one leaf?
At this point, I'm just trying to keep it alive as an experiment I guess.