Essential 

Check for Injuries.  Provide First Aid as necessary.
Check for Safety .  Utility hazards (gas, water, or sewer breaks), Electrical hazards (downed electric lines and shorts), Structural damage, and Other hazards.  
Check Utilities.  Do not shut them off unless damaged.  Do not light matches or turn on light switches until you are sure there are no gas leaks or flammable liquids.  Do not flush toilets if you suspect nearby sewer lines are broken.  
Clean up dangerous spills Wear proper hand and eye protection.  
Wear sturdy shoes, and protective clothing if there is debris. 
Do not use the telephone except to report life-threatening emergencies.   If you see a phone off the hook, hang it up.  
If you are evacuating, locate and take your pack of emergency supplies with you
Secure your home against intruders. 
Place a HELP sign in windows if you need extra assistance. 
Comfort frightened pets Confine them if necessary.  
Turn on the radio and listen for instructions from public safety agencies. 
Be prepared for aftershocks and be aware of secondary effects from the earthquake. Such as landslides, tsunamis, loose ground, etc.