American Red Cross - http://www.redcross.org/prepare/buildakit.html
The American Red Cross' site on preparing for distasters by knowing the six basics water, food, first aid supplies, clothing and bedding, tools and emergency supplies and special item for medical conditions. Comprehensive lists are provided with recommended items in asterisks.
Children's Home Pharmacy: AIPM - http://aipm.wellnesscheckpoint.com/library/banner_main.asp?P=718C02AHC2A
From the American Institute for Preventive Medicine, here is a list of medicines and other things you should keep at home for first aid.
Ready America: US Department of Homeland Security - http://www.ready.gov/index.html
US Department of Homeland Security's web site on creating disaster kits, planning for emergencies, and how to stay informed about potential threats and disasters.