Click on the following link for Boston to NYC train travel info:
"The Acela high-speed train takes ~3.5 hours, whereas the regular train typically takes ~4-5 hours. (This would compare to about 3-4 hours by flight depending on the traffic getting to and from the airport.)
Trains connect Penn Station in New York (midtown Manhattan, West 34th Street) to both Back Bay Station and South Station in Boston. Back Bay is a popular destination for many travelers whereas South Station is more "downtown" and connects to different subway (T) lines if you're continuing your journey. See www.mbta.com
for more information on local transport in Boston.
Prices vary (of course) depending on specials and how/when you purchase but generally run about $75-$100 depending on which train you take. (This would compare to airfare between NYC and Bos which can vary from roughly $100 to $600.) The more expensive trains are faster and roomier, but the cheaper trains are ok. As mentioned, Acela is the high-speed train -- as close to a bullet train as we'll see anytime soon in crowded New England with old (curvy) tracks.
Amtrak accepts booking online at www.amtrak.com,
with a major credit card. It's never too "early" to book the reservation, but you have to pay when you book. If you want to be sure to get a seat, make the reservation as soon as you are ready. Most Amtrak tickets are refundable, as long as you aren't getting a special discount fare.
Tips & tricks:
Booking early may save you money
You can get much better pricing for long distance trains if you book in advance. As mentioned, you have to pay at time of booking or several days later. One approach is to go back on Amtrak's web site and just put in some random dates a couple weeks ahead. (Make sure they are the same day of the week and time period of your actual travel plans.) Then compare the pricing to what it would be when you actually want to ride the rails. If there are no real price differences, then book your trip several weeks out rather than months. There are more than a dozen trains a day that make this journey Monday thru Friday, slightly less on weekends, so a sell out is not that common. Also, this region is all about the business traveler so fares tend to be cheaper during non rush hour time periods. There are also senior, student and AAA rates. "