Job boards are just one facet of your search. Consult individual organization/agency websites for listings and contact any organization that interests you, whether or not a relevant job is posted.
Social Work Job Bank
Professional associations can be excellent resources for job listings, upcoming conferences and job fairs, Continuing Education Units (CEUs), and online networking. A small sample:
National Association of Social Workers - The key association for the field. Check for a regional chapter in your target locale.
School Social Work Association of America
International Federation of Social Workers
American Association for Marriage and Family Therapy
Society for Social Work and Research
Association of Oncology Social Work
Geriatric Social Work Initiative
Association of Social Work Boards - Each state determines its own requirements for licensure. Links to all the regulatory boards in the US and Canada are under Find a Licensing Board.