Here is a simple but handy Open Content customized template for display before/after images
If you're in need of truly free (meaning royalty free and you don't have to pay for it) images here is a good site to check out.
This site has a nice collection of photos ranging from animals, people, places, and money. The thing that's different about this site is that everything truly is free, even for business use. That's different from a lot of advertisements you see for free images, which turn out to be just royalty free, and you have to pay and upfront price.
If you find yourself in need for some images for your site, make sure you check this website out.