National Institute on Alcohol Abuse and Alcoholism has information for parents of college students:
http://www.collegedrinkingprevention.gov/ParentsandStudents/Parents/Default.aspx

Information from the Partnership to End Addiction about binge drinking in college
http://drugfree.org/article/parents-need-know-college-binge-drinking/

Information from the DEA about substances
http://www.getsmartaboutdrugs.gov/family

Resource for Families from SAMHSA
http://www.samhsa.gov/families