Once i'm in grand central station, how can i get to jfk airport by subway? is there a direct route or would i have to catch a cab to one of the terminals once i'm near? how long's the ride and cost? is there a place w/ traveling instructions to ny schools? many of the instructions on the visitors info pages of the campuses are difficult to understand. i.e. from grand central to columbia, einstein, nyu, nymc, rochester, etc.?