In addition to selecting a size of image that is of sufficient resolution to be included in a learning object, you'll also want to ensure that the image is licensed for use and that you attribute it correctly.
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.
Use the built in filters to limit your search.
- Select on Search Tools to reveal advanced filter options.
- Select on Size.
- Select your preferred parameter.
NOTE: In addition to selecting a size of image that is of sufficient resolution to be included in a learning object, you'll also want to ensure that the image is licensed for use and that you attribute it correctly.