Photography

I have always wondered how museums handle really large photos. I can understand paintings because they come sort of "pre-mounted" on canvases, but what about photos? Say a museum received a gift of a life-sized Richard Avedon photo. How would that photo be mounted to show? Would it be framed? Glued to some kind of backing? I am not so much interested on how they attach it to the wall, but rather how do that prepare it for show. Any insights? The reason I ask is because I am thinking of making some large prints, like 40x60 or larger, but am not sure what to do once I get them.