Help! Where do you get your pictures of characters for layouts and banners?

I'm trying to make a book cover/layout for a story I'm writing and I've been all over Google looking for the right people to be on the cover. I can't find shit. Obviously, I want attractive people, but ones that aren't known (such as actors or actresses). I don't mind models, but I'm even having a hard time finding ones that don't have a huge X over them, a photographer's name or a swirl pattern. I don't want to pay for a photo, so my question is- Where do you get you pictures from?
Any suggestions or site links are more than welcome and appreciated.

Thanks in advance =)