I live in southern california and today I collected a couple PDFs that could one day be very useful, although I hope to never need them:
1) A scanned copy of my passport and birth certificate.
2) Earthquake preparedness specific documents:
LAFD equake preparedness
USGS equake preparedness:
Southern California,
Northern California
3) Non earthquake specific disaster preparedness:
Red Cross: Food and Water in an Emergency (A5055)(FEMA 477)
From Ready.gov:
"Are You Ready?" Manual,
Emergency Supply List
Interesting one I found in a blog:
Top 100 Items to Disappear First During a National Emergency (not a pdf)
Any more suggestions?