The Toronto Maple Leafs released their broadcast schedule today, and all preseason games will be televised:

Maple Leafs Preseason Schedule

Tuesday, September 18Leafs vs Ottawa at Lucan for the Kraft Hockeyville Game7:30 p.m.Sportsnet Ontario
Wednesday, September 19Leafs @ Ottawa7:30 p.m.TSN4
Friday, September 21Leafs vs Buffalo7:30 p.m.Sportsnet ONE
Saturday, September 22Leafs @ Buffalo7:00 p.m.Sportsnet Ontario
Monday, September 24Leafs vs Montréal7:30 p.m.TSN4
Wednesday, September 26Leafs @ Montréal7:00 p.m.TSN4
Friday, September 28Leafs vs Detroit7:30 p.m.TSN4
Saturday, September 29Leafs @ Detroit7:00 p.m.Sportsnet Ontario

The rest of the schedule is here in one convenient page: