Most schools in Canada don't offer an ATPL course. It's generally self study.
Aerocourse does do seminar courses in amjor centres around the country. They are based in Toronto or Mississauga.
If you go self study route, I recommend the Culhane ATPl ground school book with the Aerocourse exam book. Too many errors in Culhanes exam books. Even if you attend an Aerocourse seminar, you better have been in the books for a while. If you haven't dtudied a lick, chances are you won't be exam ready just by attending the seminar.
If your in the TO area, either Aviation World or the Prop Shop would have the books. I think you can Also find Culhane and Aerocourse on-line.
www.acceleratedaviation.com
www.aerocourse.com (?)