ALERT LA COUNTY:
 ALERT - LA COUNTY - MASS EMERGENCY NOTIFICATION SYSTEM - VOLUNTARY REGISTRYRegister here to be notified during an emergency where the public is being asked to take specific actions, such as evacuations.

USA.GOV: 
GOVERNMENT RESOURCES FOR DISASTERS & EMERGENCIES - USA.GOV:

http://www.usa.gov/index.shtml

2-1-1:
An easy to remember three-digit dialing code that enables a caller to access information about more than 28,000 health and human service programs throughout Los Angeles County 24 hours a day, seven days a week and is TTY accessible. 211 LA County, formerly known as INFO Line of Los Angeles, has been providing these services since 1981.

OTHER SERVICES
Disaster Preparedness Checklist http://www.lomita.com/cityhall/images/pdf.gif
Earthquake Safety http://www.lomita.com/cityhall/images/pdf.gif
LA County's Emergency Survival Guide http://www.lomita.com/cityhall/images/pdf.gif
Emergency Preparedness site  (San Francisco-centric, but still very useful)