When getting to Flushing-Main Street gets tough because the 7 is under construction... or when the N is too slow to Queensboro Plaza, get a $3.50 one-way CityTicket and get to Flushing in 2 stations!
Beware the gap. Get out of the way when you see someone running. Mind the sleeping hobos in the waiting room -- there's a reason why no one is sitting around that one person.
Thirsty for a Coke? Buy it at Kmart. The machines just inside are $0.75 for a can, $1.25 for a 20oz. bottle. I dare you to find somewhere cheaper in Midtown.
This place sucks, very busy and not clearly signposted. Departures only announced 10 mins beforehand so check the arrivals board for your track number.
Considering how many bodies this thing moves every day it's pretty impressive. The shops don't suck either. There are decent places to eat and drink if you are in the know.
Penn Station is the major intercity train station and a major commuter rail hub in New York City. Serving 300,000 passengers a day at a rate of up to a thousand every 90 seconds, it is the busiest passenger transportation facility in the United States and by far the busiest train station in North America.