The guide What to do in the event of death (PDF), available for free on the Services Québec - Citoyens website, lists all the steps to be taken after a loved one dies. The guide includes a list of documents needed to liquidate a succession, a checklist of what to do, and several definitions.
The guide also lists certain steps that can be taken proactively, such as appointing a tutor for your child, and others that must be taken with the Curateur public du Québec if an incapable person, for whom you are the mandatary or tutor, dies. Feel free to ask for more information. For more information, see the page What to do in the event of death.