It's really a single terminal these days. But its clean and bright. Get nexus if you ate going to fly to the USA often. The immigration lines can otherwise be very annoying. Plus you look very important as you confidently stride towards the eye scanning alternative to a human.
Aircanada maple leaf lounges are the best in their genre. So hopefully you have access. If not there's a pay lounge but that's silly. Just go to the molson bar.
Try not to fly usairways. They make Toronto look bad but i suspect it's not TOs fault.
Stay at the Sheraton gateway if you arrive late or leave early.