My first thought on seeing the subject of WW1 trench warfare was to drop a link to the Hardcore History WW1 podcasts. They are excellent at getting across the sheer horror and enormity of WW1, something that was lost on me growing up in the US (we tend to focus on WW2). I suspect European listeners will be surprised by less, but for any American who doesn't know what I'm talking about if I mention Verdun or the Somme, I _highly_ recommend the podcasts. They are ~12 hours (so far) and riveting.
Exactly right about how U.S. education seems to put more emphasis on WWII than WWI. And then even within WWII you don't get the whole story. Carlin's "Ghosts of the Ostfront" series gave me an entirely new perspective on the side of the war the U.S. didn't fight. In many ways - certainly in terms of lives lost - it's an even more tragic story.
It's not just the USA. Here in Finland I was pretty much only taught how the war started and how it affected Finland (which gained independence from Russia in 1917, and then fought a civil war in 1918 with some involvement from Russia and Germany). My teacher openly told us that we don't need to know any details about ww1, since ww2 is much more important (although the teaching about that one also emphasized the Finnish wars (winter war, continuation war and Lapland war) more than the ww2 itself).
Every country focuses on teaching history relevant to itself. Before I married my wife, who is Chinese, I knew next to nothing about the wars of Japanese expansionism in east asia that lead up to WW2.
If you've ever wondered why europe has been so secular/atheistic for the last 100 years, in comparison to the rest of the word, the Somme is basically your answer.
Could you elaborate? To me it's not particularly obvious why a particular battle should change the religious landscape of a continent for a century to come.