If you are using material created by others in your podcast (audio, video, images, etc.), there are copyright considerations and you may not be able to just cite the source. Whether you need permission or not from copyright owner(s) depends on
The Copyright Office (firstname.lastname@example.org) is happy to help you understand how to use copyright-protected material. Often it is easier to search for and include material with few copyright considerations, which also helps with re-using your podcast beyond your assignment and distributing it more widely.
Music, Videos, and Images
Music and videos may have multiple layers of copyright and many copyright owners, which makes it difficult to obtain permission. Images tend to be less complicated for seeking permission from a copyright owner. It is often easier to search for and use material with permissive licenses or in the public domain.
The copyright owner of a work has the right to apply a license that grants copyright permission for someone to use the work according to the terms of the license. You don't need to ask permission if your use is permitted by the license. If your use is not permitted, then you would have to ask the copyright owner for permission.
Open Sounds, Videos and Images has links to sources for finding no-cost royalty-free, Creative Commons, and public domain material.
Note that you can also purchase a license for royalty-free music, videos, and images from various sites.
Just because something is publicly available does not mean it is also in the public domain! Public domain refers to works that belong to the public:
"Works can be in the public domain for a variety of reasons. Examples: the term of the copyright has expired, the work was not eligible for copyright protection in the first place, or the copyright owner has authorized the public to use the work without permission or payment." Source: About Copyright
Materials in the public domain are not copyright protected and you may copy and distribute them. However, finding and using public domain materials can be tricky. Consult this helpful Public Domain Guide and/or Public Domain Flowchart.
A note about logos, brands, and trademarks
Copyright law and trademark law may be relevant if you are using logos, brands, and trademarks in your podcast. Please contact email@example.com for further information.
Most uses of copyright-protected material in a podcast would not be permitted under the fair dealing exception in the Copyright Act, especially if the podcast is not directly commenting on, criticizing, or reviewing the material (i.e., the material is used to enhance the look and feel of the podcast, such as music for intros and outros). However, if you think your use may be permitted under fair dealing, contact firstname.lastname@example.org for support conducting a fair dealing analysis.
For student assignments, the student owns the copyright in the work they create, though not for any of the third-party materials they use. As the copyright owner, you may choose to apply a Creative Commons or other license to your work to make it easier for others to share and use it. For more information on applying licenses to your own work, contact email@example.com