Whether you piece together a first aid kit or buy one fully assembled, the American Red Cross advises you to keep one at home and another in your car. Inspect each kit on a regular basis to make sure your supplies are fresh. Check the expiration dates on all medication and make sure the packaging on sterile equipment hasn't decomposed or been nibbled on by animals or insects.
The Red Cross: Anatomy of a First Aid Kit
American College of Emergency Physicians: Home First Aid Kits
Ready.gov: Get a Kit
The Red Cross: CPR, First Aid and AED
Washington, D.C. Metropolitan Police Department: 911 Emergency Number
Courtesy of LIVESTRONG.COM