National

CPNI – Centre for the Protection of National Infrastructure
http://www.cpni.gov.uk

Warning, advice and reporting point (WARP)
http://www.warp.gov.uk

 

International

European Government CERTs group
http://www.egc-group.org

European Network Information Security Agency
http://www.enisa.europa.eu/

Forum of Incident Response & Security Teams (FIRST)
http://www.first.org