The best book is by Desmond Morton called "When Your Number is Up". It is a social history of life in the trenches.

The Canadian War Museum website has an interactive story that lets you make decisions while reading a story about a soldier in World War One; there are multiple endings depending on the choices you make.

In Toronto, the 48th Highlanders of Canada regimental museum is located on King Street, just West of University Avenue in the basement of the Regimental Church (just East of Roy Thomson Hall)

You might get some extra marks for seeking out additional information from these other sources (i.e. showing that you put in some extra effort and went the extra mile, as opposed to simply snorkelling the Net or visiting the library).

I completely agree with the recommendation you should read VIMY, and in my personal library I've got an excellent book in my own library specifically on trench warfare (but, I can't remember the exact title right now, even thought it's something like "Trench Warfare ..." - will have to look it out for you)

Good luck with your project, and we hope you get a good mark.

Dileas Gu Brath

You may already have heard of this link, but just in case you haven't...
My younger brother introduced me to "Ask Jeeves" - a really useful, general purpose Internet search/reference site: http://www.askjeeves.com/
(I did a search on "trench warfare", and a gazillion hits came up)

Also, it dawned on me you might be able to use a famous quote as part of your introduction (I routinely abuse and overuse quotes, and haven't flunked a history course yet ...), so here goes:

"My God, did we really send men to fight in that?"
(Lieutenant General Sir Launcelot Kiggell: On seeing the terrain and the mud after the battle of Passchendaele, 1917)