When re-using images in your educational materials, you'll want to play if safe by only using images that have been licensed for this re-use. Often, even though you're "allowed" to re-use them, there is a requirement to provide attribution as part of your learning object.
Open your browser and visit Google.com

Visit www.google.com
- Type in your search terms.
- Select on "Google Search."
Select on Images Tab.

- Select on the images tab to migrate from a regular web search to solely an image search.