Google Images is familiar and easy to search - and they make it relatively easy to find images you can use fairly.
To sort by reusable images, run your search term. Then choose the "Search Tools" button from the toolbar. Select "Usage Rights" and then "Labeled for Reuse" or "Reuse with modification."
Flickr is another site that works hard to provide transparency about which images you can use and which are copyrighted or "rights reserved."
After you run your search, look for the drop down box labeled "Any License." Switch to "Creative Commons" or one of the other options that allows for modification or reuse.
The Google Cultural Institute is a database for images from museums, fine art galleries, and cultural institutions. They have an extensive collection of high quality images and a related YouTube channel with thoughtful videos and tips for how to use the Cultural Institute.
The only tricky thing with this one is that the images aren't easy to download. In most cases, you'll need to check what museum provides an image and then head for the museum's website to download.
Getty Images usually requires a subscription BUT they've made 66 million images available, free of charge and free/fair access, for embedding in websites and blogs. Click on the image to search and use images from Getty.
Alternatively, you have the option to search directly through our Squarespace website. When you add an image to a page or post, you can click the option to search Getty Images instead of uploading a file.