Practice Setting
Social Workers are usually employed in hospitals, community health centers, mental health clinics, schools, advocacy organizations, government departments, social service agencies, child welfare settings, family service agencies, correctional facilities, social housing organizations, family courts, employee assistance programs and private counselling, school boards, and consultation agencies.

Below are links that describe what social workers do when they work in various areas of practice.  You may also be interested in the Canadian Insititute for Health Information's page on social work.