Many disaster-preparedness guides are hardcore; they assume that you can afford to dash out and buy a three-month food supply right this second
and that you have the dedication to stock haz-mat gear in your basement.
If you are more concerned with being able to live without electricity for five days than with purchasing gas masks, and you want guidelines for a basic evacuation kit rather than a comprehensive list of what to take when you run for the hills to live off the land, Just in Case: How to Be Self-Sufficient When the Unexpected Happens is the book for you. Kathy Harrison outlines a step-by-step plan that will allow you to steadily enhance your disaster preparedness within a budget and along a time-frame. (She understands, for example, that you will want a system for rotating through your stockpiled food instead of waiting until it expires and then discarding it, or living off it exclusively for the three months beforehand.)
This is a sensible, friendly, thoughtful, readable household guide, full of useful anecdotes about Harrison's own mistakes and successes as she built up her family's self-sufficiency.