Here is the link to Library and Archives Canada's research portal for military records: http://www.bac-lac.gc.ca/eng/discover/military-heritage/Pages/military-heritage.aspx
The records on the WWI soldiers are fairly complete - complete service files for men surnamed 'A' to 'P', attestation papers for all soldiers, 'Circumstances of Death' cards for most and war diaries.
For WWII, unfortunately, far fewer of the records are either open or available electronically. because of the 70 year rule, actual service files can only be accessed - I think - by relatives. If the spouse or child of a serviceman/woman requests the records in writing, with proof of death, they can get it. Otherwise, there is a list of published records at the LAC site.
Medal entitlement is not to difficult to make an educated guess at, for WWII and Korea, and Veterans Affairs and other sites will tell you the qualifying period for each medal. So, for example, if you know an uncle went to Europe with an armoured unti, he almost ceratinly earned the 1939-45 Star, either the France & Germany Star or the Italy Star, the Canadian Volunteer Service Medal with bar for overseas service and the Defence Medal. Canadians in Korea earned the British 'Korea' medal and the UN Korea medal, in general. Check here for descriptions of some: http://www.veterans.gc.ca/eng/remembrance/medals-decorations
I hope this is of some help. feel free to post other questions or contact me if you like.
Peter