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
Select on Images Tab.
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.