Homeless Resources in the United States:

Hud's Homeless Website

http://www.hud.gov/homeless/index.cfm
Hud's Homeless Resources for Virginia
http://www.hud.gov/local/index.cfm?state=va

Information on Homelessness:
Wikipedia's article on homelessness
http://en.wikipedia.org/wiki/Homelessness

Non-Governmental Organizations:
An international site for homeless issues
http://www.sparesomechange.com/homeless.asp
National Association to End Homelessness
http://www.naeh.org/
Artists helping the Homeless
http://www.artistshelpingchildren.org/shelters.html
National Center for Homeless Education (working under a grant from the Department of Education)
http://www.serve.org/nche/