There are many, many places online where you can find video, graphics, music, and font resources you can legally use in your creative projects.
Before you explore those, you might consider the opportunities your project presents. Do you know someone who can draw? Have them do your illustrations in exchage for credit. How about someone who composes music? Try using their music in exchange for credit. Take your own pictures. Every creative endeavor is a chance to raise others up as well as yourself!
This is also an opportunity to educate students on the value of protecting their work.
CopyfreeResources - Collection of copyright free resources maintained by Jo Meyertons
Baylor University "Free Stuff or Nearly Free"
Cornell University Legal Sources for Online Music and Videos
Here’s a handy reference from Cornell about copyright length and terms, including what I like to call “the Disney law’ (<1923, 95 years after publication – certain to be lengthened in 2017) and “the RIAA law” (<1972, 95 years – that’s 2067):
I also have these things from the Center for Social Media
PDF manual – Online Best Practices in Fair Use
TED Talk by Lawrence Lessig, which he also gave at AEJMC – great stuff, but 18 minutes,
10 minute primer on copyright law, ripped entirely from Disney films: A Fair(y) Use Tale