Around a 10 minute taxi ride. Be aware if you are traveling to NYC, and you get on the Canadian side, your first stop is on the U.S. border. It's mandatory to get off the train, and your luggage, to go through customs. If the train is full, that can take around 2 hours. Also, although the Amtrak trains are spacious and comfortable, the food isn't great, it's expensive and the queue is very long. Take your own.
We go a taxi from in front of the hotel, about a 10 minute drive and it was 10 dollars . That was to the Canadian side station,if you need any more info just ask.
3 km. You can drive from there or take a bus 104.
There are 2 train stations in the Niagara Falls area - one is on the U.S. side and one is on the Canadian side (they are just across the Niagara River from each other).
From the Canadian train station - it is about 3 km to the hotel. (about a 6 minute cab ride)
the answers above are better than mine
Get an answer from Sheraton on the Falls staff and past guests.