Please note that it is your responsibility to check each site to make sure your use is covered according to their policy. In some cases media can be used in class but cannot be posted to the web or used in a contest submission, so double-check before using it. When in doubt, always ask the creator!
You can use this Fair Use checklist to determine whether the media you want to use meets Fair Use Guidelines. Fair Use Evaluator Tool
According to Fair Use, you must CITE THE SOURCE using MLA formatting for any works you did not create yourself, even if the use falls under Fair Use! Many of the sites will tell you how to do so for media used from their site.
Use mybib.com to help you cite your source!
Images
*Remember, just going to the Internet and copying pictures could be copyright infringement if the picture you copy is copyright protected, so make sure you use a site that has copyright friendly pictures or do a Google advanced search and narrow the results to those that are "free to use or share".
Click on the picture to see a list of copyright friendly resources for images and music/audio.
OR
Create a picture with text on it
Use an image generator like imagechef.com
Paste a picture in PowerPoint, add text, and save it as a jpg
OR
Use your own picture!