Be aware that there isn't an underpass, and many of its entrances/exits have been closed over the years, leaving the southernmost part of the station with most of the access points to the street. Avoid being in the north end of the train if you wish to get out of the subway quickly after getting off the train.
The lower level is served by the E train at all times, and the upper level is served by the C train at all times except late nights when A train takes over service.