Rachel Carson (International Livestock Research Institute -Flicker)
Windmill (Max Pixel)
General Images
WEB RESOURCES
IMPORTANT: Use of images is subject to U.S. copyright law. If an image is copyrighted, you must ask permission--and often pay--to use it with an accompanying credit line. That's the law! If an image is in the public domain and thus freely available to use, often it will say so and provide credit information.
If you are not sure if an image is public domain, contact the person or entity responsible for the image and ask permission for one-time educational use with an accompanying credit line. For more on copyright, see U.S. Copyright Office FAQs.
The best sites to find copyright free images:
Government sites
Wikimedia Commons
Flicker
Google Images (advanced search):
NOTE:To find copyright free images using Google , follow these steps: