A lot of the photographs from the Western Front in World War One are staged, to some degree or another. Only official photographers, authorized by the government, were allowed, and naturally it was in the best interest of the government to show a certain version of war. There is emphasis on the best (all right, least bad) parts of the experience and the heroism of the soldiers. A sense of the experience is certainly present, but it's only very rarely the experiences of horror, terror, and misery. However, there are exceptions, and I've collected some of the photographs that I feel bring us closer to the experience of the soldier on the Front than most.
If you're interested in the contrast between the propaganda view and the reality, I also recommended having a listen to the clip below, 'Here We Are Again' while you go.
A soldier flinging himself to the ground to avoid flying shrapnel from the nearby bursting shells. His instinct is so rapid that he's slightly blurred in the photograph. Source
A desolate section of trench at the front named 'Hyde Park Corner'. Source
A flooded trench (unfortunately hardly an unusual occurrence). Source
Machine gunners at an improvised post. Source
A shell bursting just 10 yards in front of the photographer, with flying debris. Source
And the absurdity of war-- a sergent with a sunshade he has found undamaged amdist the ruins of a village. Source