Qantas077: You'll head out of town to the west on Highway 2, which is the Gardiner Expressway in Toronto - depending on where you're staying - you'll take the Gardiner if you are in downtown Toronto. If you're farther north or east or west, you'll have to ask for directions. Do you know where you are staying? The Gardiner then becomes the Queen Elizabeth Way. You'll take the QEW all the way to Niagara Falls. There is good signage once you get to NF
about how to get to "The Falls". Don't hesitate to ask for directions if you get lost or are confused. It's a very safe area. Traffic between Toronto and Burlington WILL be heavy. Be careful.
You'll cross over two very large bridges: the Burlington Skyway and the St. Catherines Skyway (also known as the Garden City Skyway, if I'm not mistaken). If you are interested in shipping, the Garden City Skyway is a bridge over the Welland Canal, that connects Lake Erie to Lake Ontario. Obviously boats can't go over the falls.
The Welland Canal is really interesting because these huge ships are raised and lowered in the locks. You can make a detour to see the canal.
As you're driving after Hamilton watch for a cliff on your right. That's the Niagara Escarpment. That is the same land feature that the falls go over. It goes for miles and miles.
If power generation interests you you can drive up the Parkway from the falls and you'll come to the Sir Adam Beck generating station. It's huge!
There's also a lot of wineries in the Niagara area.
If you really don't want to drive you can take the train to Niagara Falls. If it hasn't changed, there's a VIA
train between Toronto and Niagara Falls. But the drive is pretty too.