1. Food storage (long term and short term)
2. Water storage
3. Financial reserve
4. Medical/First Aid
There are several websites with tools to help you assess your needs and get you on your way to being prepared. Here are a few of my favorite-
provident living.org- Food & water storage techniques, food storage calculator, etc.
Costco.com- they are now selling long term foodstorage items at a great value
Emergency Essentials- Food Storage Analyzer- create a printer friendly inventory of your food storage that includes a breakdown of nutritional value & calculates the number of days your food supply would last. This is a great tool to help you ensure that you not only have food, but that is nutritionally balanced! Plus if you tyr out their food storage anyalyzer and write a review you get a free $10 gift card to use on their products.