I went out this morning and the car won't start. The battery seems fine, I don't have any way to test it. The car will make one click when I try to turn it over and nothing. I'm thinking the starter is bad. Any tricks I should try before I have is towed to the mechanic?

Sounds like the starter to me.

Recap:
I went out later that day and tried again. Got the single click, and then it turned over. It's been running ever since with no problems other than occasionally it will turn over more than usual before starting. Any ideas what I can expect to die in the near future? Alternator, starter is on the way out, maybe it is the battery?

Try removing , cleaning and re-installing both connections at the battery and see it it helps.

If it happens again try tapping the starter while someone holds the key on.Then if it works the starter will need to be replaced.