Using copyrighted material in course slides for display only:
The Copyright Act's exceptions for educational institutions (section 29.4) allows you to "reproduce a work, or do any other necessary act, in order to display it" in a class for teaching purposes, as long as there is no commercial version available that is appropriate for the use. This exception does not cover the distribution of copies of copyrighted work, in electronic or paper form.
Using copyrighted material in course slides to display and distribute:
While educational exceptions allow reproduction of copyright protected material for display purposes, the exceptions do not apply for distributing the slides in Moodle or sharing by other means with students. For slides that will be shared you will need to ensure you are within the limits of Fair Dealing or an educational exception in the Copyright Act (such as section 30.04 Works available through the internet), or you have permission.