Public Domain or Creative Commons
Other good image resource options:
Super simple to use, Canva gives you everything you need to design logos, infographics, and more! Learning how is as easy as watching the 23 second (really!) video and choosing the elements you'd like to include.
With three levels to choose from, Pixlr let's you edit images regardless of your experience level. Pixlr-o-matic offers a fun approach to people who want to play around with their images. Pixlr Express provides a way to quickly and efficiently tweak a photo. And Pixlr Advanced provides seasoned photo editors the features they need. Apps for Apple and Android devices too! The Advanced Editor is available in Google Chrome.
Use PicMonkey to crop and edit photos, apply cool effects, create collages. This is a fun and easy to use online editor that offers tons of "scrapbooking" style features. Apps for Google Chrome and for Facebook!