If you are working on a school assignment, your work probably allows you to take advantage of the "Fair Use" doctrine.
What is Fair Use? Fair Use is a legal doctrine that allow the unlicensed use of copyrighted material in certain situations, under certain circumstances, to promote freedom of expression. Nonprofit education is generally recognized as one of those circumstances.
What does that mean? That means - AS LONG AS YOU CITE YOUR SOURCES - you can quote other works and borrow images and creative content for your school work.
Still nervous about violating copyright? Want to be extra careful when using images? Find Images that have Creative Common Licensing. A CC license allows other people to share, use, and build upon the work of another.
Finding Creative Common Images Using Google Using Google, search for the image you want, select the Images section. Click on “Tools” to expand the filter menu. Under “Usage Rights,” you'll find the option to sort images by their license Choose Creative Commons