Copyright and Fair Use: Using Images Ethically

"Our tools give everyone from individual creators to large companies and institutions a simple, standardized way to grant copyright permissions to their creative work. The combination of our tools and our users is a vast and growing digital commons, a pool of content that can be copied, distributed, edited, remixed, and built upon, all within the boundaries of copyright law." website

Usage and citation information is described here: http://www.getty.edu/about/whatwedo/opencontent.html

"Search millions of photographs from the LIFE photo archive, stretching from the 1750s to today. Most were never published and are now available for the first time through the joint work of LIFE and Google." website

"The Metropolitan Museum of Art is committed to making a broad range of digital images of artworks in the public domain widely and freely available for scholarly and academic publication. To assist in navigating the vast image content on this website, the Museum has implemented Open Access for Scholarly Content (OASC). " website

"Wellcome Images is one of the world's richest and most unique collections, with themes ranging from medical and social history to contemporary healthcare and biomedical science." website

"Wikimedia Commons is a media file repository making available public domain and freely-licensed educational media content (images, sound and video clips) to everyone, in their own language." website

"all photos on Pexels are licensed under the Creative Commons Zero (CC0) license. This means the pictures are completely free to be used for any legal purpose.
The pictures are free for personal and even for commercial use.
You can modify, copy and distribute the photos.
All without asking for permission or setting a link to the source. So, attribution is not required."

"Pixabay is a vibrant community of creatives, sharing copyright free images and videos. All contents are released under Creative Commons CC0, which makes them safe to use without asking for permission or giving credit to the artist - even for commercial purposes." website

Whether you are posting or setting up pages/walls/etc....lots of different resources are here.