You can start here and order his service record:
Find the particulars of his record here:
http://www.collectionscanada.ca/02/02010602_e.html
How to order copies of First World War service files
http://www.collectionscanada.ca/02/0201060101_e.html#consult
Once you have his service record (it takes about 4 weeks to get it from the Archives, and 40 cents per page), you will find that his record of service will give you a good idea of where he was throughout the war.
Next, you can find the War Diaries for his unit(s) here:
http://www.collectionscanada.ca/02/020152_e.html
You might also find additional research advice here:
Canadian Expeditionary Force Study Group
http://www.cefresearch.com/phpBB2/index.php