Subway Operator

[americanaviator]

Hi everyone, first time poster here! I'm writing a story in which the main character works in the subway. i haven't fully decided yet if he's going to actually drive or have some other job (possibly maintenance related?) but my basic problem is that the only thing I know about the subway is how to ride it. So I was hoping someone could come to my aid and tell me:

A) What the job of a subway driver actually entails 
B) What are some other regular jobs in the subway, and what they entail

Thank you all so much, and sorry if my question is poorly worded!

ETA: This is specifically about the New York subway, sorry guys!