Below are a list of non-profit organizations for caregivers.
Caregiver Action Network: provides a plan for caregivers in different stages of the caregiving process (ie: just getting started, being a caregiver for years)
Well Spouse Association: An association for spousal support as they take on the role of caregiver for their loved one.
Family Caregiver Alliance: An organization that advocates on behalf of caregivers, connecting them with caregiving nonprofits and programs in their area, and providing resources to families.
Family Care Navigator: Caregiver services by state, using an interactive map
For children who are caregivers:
American Association of Caregiving Youth: An organization for children who are caregivers, helping to provide academic and other types of support.