ESRI                                                       http://www.esri.com/

ESRI Mapping Center:                   http://mappingcenter.esri.com/

ESRI Online training:                      http://training.esri.com/gateway/index.cfm

CGIA                                                      http://www.cgia.org/

Geonetwork                                       http://geonetwork-opensource.org/

GISCI                                                     http://gisci.org

Inland Empire GIS User Group    http://www.iegis.org/iegis/index.php