‘Sounding English’
This is a great link. Although it’s American, the pronunciation is close enough to Canadian to make it very useful. The cross-section diagram of each mouth sound will help you visualize the ‘mouth gymnastics’ required for each sound. There are also videos to accompany the diagrams: they demonstrate various mouth sounds with head-on and side-view camera angles.
‘Voice Guy’
This is an ideal resource for voice warm-ups. This site looks at what goes into making different sounds. The webmaster, Eric Armstrong, is a York University professor with the theatre department. He focuses on helping students do voice warm-ups, such as how to relax muscles and lower breath. There are video and audio exercises to guide you through.