Unless your plan to create original images or video clips for your media production, it is essential for you to understand Copyright and Fair Use when educational materials are being created.
Copyright
Without exception, when a created piece using another person's work generates revenue, copyright law requires getting permission to use that created piece from it's owner. Any fees required for that permission is legally due to the owner of that created piece.
Fair Use
However, when media pieces are created for educational reasons it is possible to use copyrighted materials in a somewhat limited degree without acquiring permission from its owner. Columbia University has an extremely useful checklist for clarifying acceptable Fair Use from unacceptable Fair Use. Please consult with this document to ensure your media piece is in compliance with Copyright and Fair Use legal requirements.
For additional information, Bitlaw: A Free Legal Resource Focusing on Intellectual Property has more information on the topic in their Fair Use in Copy Right Law post.
Video created by Common Sense Education. "Common Sense Education offers free resources for teaching in the digital age."
THINGS TO CONSIDER