Probably the best way to get there is to take the C or E train from Penn Station to the 23rd street stop or the 1 train to the 28th street stop. However, to be completely honest, you could walk from Penn Station to 208 W 23rd Street in around 10-15 minutes.
No, the AirTrain takes you to and from the subway, and the subway takes you to and from Penn Station. Take the AirTrain to the Howard Beach Station, and get the Manhattan-bound A train (of the A-C-E, the blue line) to 34th Street-Penn Station.
Take the Downtown 2 or 3 trains (of the 1-2-3, the red line) from 34th Street-Penn Station to Wall Street (at William Street).
Take the Uptown E train (of the A-C-E, the blue line) from 34th Street-Penn Station to Court Square.
Take the Uptown 1-2-3 (the red line) from 34th Street-Penn Station to 42nd Street-Times Square, and transfer there to the N.
Take the Uptown 1 train (of the 1-2-3, the red line) from 34th Street-Penn Station to 66th Street-Lincoln Center (at Broadway).
Take the Downtown 1 train (of the 1-2-3, the red line), 1 stop, from 34th Street-Penn Station to 28th Street (at 7th Avenue).
Yes, the 3 train stops at Penn Station. All trains on the 1-2-3 line (the red line) and the A-C-E line (the blue line) stop at Penn Station.However, the 3 does NOT stop at Penn Station from 11:30 PM to 6 AM. During those times, the line ends at 42nd Street-Times Square.
The A train (of the A-C-E, the blue line). Take the Downtown A train from 175th Street to 34th Street-Penn Station. Entrance to the 175th Street station is included inside the bus terminal complex.
You don't have to take the subway; it's 2 blocks. Penn Station is at 34th Street between 8th and 7th Avenues, and 520 8th Avenue is between 36th and 37th Streets.
Walk west to Lexington Avenue and north to 53rd Street, and take the Downtown E train (of the A-C-E, the blue line) from Lexington Avenue-53rd Street to 34th Street-Penn Station.
Take the Uptown 1-2-3 (the red line), 1 stop, from 34th Street-Penn Station to 42nd Street-Times Square.Transfer at Times Square to the Uptown N-R-Q (the yellow line) to 59th Street-5th Avenue or 59th Street-Lexington Avenue.
Take the Uptown 1-2-3 (the red line), 1 stop, from 34th Street-Penn Station to 42nd Street-Times Square.Transfer at Times Square to the Downtown N-R-Q (the yellow line), and take the Downtown N-R-Q to Canal Street (at Broadway). This station is located in the heart of Chinatown.