There are many organizations that work to support military personnel and their families.  Here are a few:

http://www.militarychild.org/ is a non profit organization which provides educational resources and support for military children.
 
The Injured Marine Semper Fi Fund, which provides financial grants and other assistance to wounded Marines, sailors and their families.

 Fisher House Foundation, an organization that provides "a home away from home" for families of patients receiving care at major military and VA medical centers throughout the country and overseas.

If you're a veteran or volunteer looking for a V.A. facility in your area, visit the Department of Veterans Affairs Web site's Facilities Locator & Directory.