Photographs say so much. They really can be worth a thousand words, and sometimes go beyond the power of words. The visual imagery is a great force for understanding and insight. Photography books (a.k.a. "Coffee Table Books") litter my tables, countertops and bookshelves. They can take you around the world and through time and can spark imagination and emotion in a way unique to photography. The realness of it, the truth of it, seems like history caught in time, without the filters of secondary sources or media or opinion. (Photoshop and its ilk change that, but nonetheless.)
I would use photographs on a daily basis in my classroom. As a potential writing prompt, a doorway into the next history investigation, the next science inquiry. I would encourage my students to be both consumers and producers of quality photography.
Teach your passions, I guess.