If you're in need of free images to use, take a look at LibreStock. It's a database of over 36,000 images that you're entirely free to use however you want. The images are pulled from a variety of different sites (though excluding Flickr for example) and they are of a good quality. Here's a screenshot for a 'library' search:
Click on the image that you want, and you get taken to the appropriate website, where you can then download it. It's not the biggest database out there, and regular readers will be aware that there are plenty of other engines out there, but it's certainly good enough to add to your lists!