National Criminal Justice Reference Service (NCJRS) is a federally funded resource offering justice and substance abuse information to support research, policy, and program development worldwide. They have a significant library of gang information available to sort by title and date. Everything from evaluation of gang intervention programs to national youth gang surveys.
Institute for Intergovernmental Research's (IIR) National Youth Gang Center conducts assessments of the scope and characteristics of youth gang activity in the United States, develops resources and makes them available to the field, and provides training and technical assistance in support of community-based prevention, intervention, and suppression efforts. They have a compilation of gang related legislation by state, a listing of promising gang program strategies, links to news articles, publications and you can sign-up to join a Listserv (GANGINFO) for discussion of suppression, intervention and prevention of youth gang crime.
Office of Juvenile Justice and Delinquency Prevention (OJJDP), The Office strives to enable the juvenile justice system to better protect public safety, hold offenders accountable, and provide services tailored to the needs of youth and their families. They have a great search engine for model programs, host for Communities Respond to Youth Gangs in America 8/11/2005 Videoconference 1:30 p.m. to 3 p.m. ET, Satellite/Web based, list of relevant OJJDP publications, programs, funding opportunities, events, and other resources.
Center for Substance Abuse Prevention at SAMHSA Substance Abuse and Mental Health Services Administration, offers a strategic prevention platform, research-based model programs list, national survey data, links to all kinds of resources and interactive tools for problem assessment, capacity building, planning, implementation and evaluation. Programs effectively addressing risk and resiliency factors produce positive outcomes useful for both drug and gang prevention.
The U.S Department of Education's Higher Education Center for Alcohol, Drug Abuse and Violence Prevention provides information regarding various initiatives and a clearinghouse for publications on alcohol and other drugs and related subjects such as bullying, violence and gangs.