An official fund for victims' families, and the community as a whole, has now been established: The Sandy Hook School Support Fund, set up by the United Way of Western Connecticut will provide support services to families and the community. All donations to this fund will go directly to those affected.
You can send words of support and messages for families affected in an evergram here. They will be collated and given to the families in the future.
The Connecticut Department of Emergency Services and Public Protection says anyone wishing to volunteer should call 211 or (800) 203-1234.