(1) Organizations concerned with crime and criminal justice

Bureau of Justice Statistics
http://bjs.ojp.usdoj.gov/

Campbell Collaboration
http://www.campbellcollaboration.org/

Center for Evidence-Based Crime Policy
http://gunston.gmu.edu/cebcp/

Center for Problem-Oriented Policing
http://www.popcenter.org/

International Association of Crime Analysts
http://www.iaca.net/

Home Office (U.K.) Research & Statistics
http://www.homeoffice.gov.uk/rds/index.html

National Criminal Justice Reference Service
http://www.ncjrs.gov/

(2) Professors with helpful websites

Professor Geoff Alpert, University of South Carolina
http://www.deadlyforce.com

Professor Charis Kubrin, University of California at Irvine
http://socialecology.uci.edu/faculty/ckubrin

Professor Jerry Ratcliffe, Temple University
http://jratcliffe.net

Professor Rob Sampson, Harvard University
http://www.wjh.harvard.edu/soc/faculty/sampson/

Professor Wes Skogan, Northwestern University
http://www.skogan.org

Professor Ralph Taylor, Temple University
http://www.rbtaylor.net

Professor Samuel Walker, University of Nebraska at Omaha
http://samuelwalker.net/

Professor Ron Weitzer, George Washington University
http://www.gwu.edu/~soc/faculty/weitzer.cfm

(3) Other sites

Mplus (terrific statistical modeling software)
http://www.statmodel.com