It’s always the same question from each and every customer. Where do you find the images? are they free to distribute – make commercial use?.
First answer its pay a monthly fee for a good image stock service. But if theres budget limitations, yep, could be done, and its pretty simple. There are various sites, some truly free stock photos, some kind of fake, but the best place it’s Flickr.
Just need to make the proper searching. This URL sets Flickr to show only CC licensed images, for commercial use and/or free to modify.
Of course, read carefully each author’s licensing terms, and please make a clear attribution to them. It’s fair.