Car Rental Help (Toronto Vacation)

Will heading for Toronto on sunday, for 5 day vacation.

I’m gonna need a rental car for those 5 days, to get around. Planning seeing as much as possible.

I’ll be arriving at the Pearson airport btw.

Anyway, being that this is the first time I renting a car, I was looking for a little help and some pointers on renting a car.

I’d like to prebook my car over the net.

Are these car rental firms located at the airport?

Any recomondations on any companies?

Big TIA!