Happily, the official histories of the Canadian Army are available online. The main volume you'll want is Official history of the Canadian Army in the Second World War, Vol II The Canadians in Italy, 1943-1945, which you can read at https://www.canada.ca/content/dam/themes/defence/caf/militaryhistory/dhh/official/book-1956-army-ww2-2-en.pdf (the first 180 pages are about Sicily).

For a more complete overall picture of the Italian campaign, you might also want to check out The Day of Battle: The War in Sicily and Italy, 1943-1944, by Rick Atkinson, which as far as I know is very well regarded (it's on my list to-acquire for my military history library).