If you are using an image/video clip/sound clip/etc. for a presentation IN CLASS only, then you are probably within Fair Use and just need to cite your sources.
BUT, if you make your project available online without the express permission of the copyright holders of the images, etc., then you are probably infringing on copyright. There are some great resources out there to help you find materials that are in the public domain or provided for reuse by the creator. And don't forget, if you take a photo or record video/music/sound, etc., YOU own the copyright to that material and can use it any way you like!
These sites provide access to public domain or creative commons licensed images - that means the photographer has given you permission to use them in a project!
When doing a Google Image search, click "Tools" and then select "Creative Commons licenses" to see images that are free for you to use.
Some guide content used with permission from Atlanta International School and The College of William and Mary
Use the databases to find images and citations that the photographer has given you permission to use!