Much of what has been said here is good. However I would like to add a couple of more points.
Firstly you can't prepare for every kind of natural disaster or emergency. So don't bother. Luckily, the area were you are living now, most likely has only one kind risk. You might live in a earthquake zone, an area prone to flooding or fire, so just focus and plan for that.
Secondly, understanding whether your disaster is a local event or a regional one, should influence your decision to go or stay. So gather reliable intel ... not hearsay.
Finally, 95% of all people leave things too late. Its far better to evacuate over nothing (and laugh about it after), than being trapped with everyone else. Remember, if you have to see the danger with your own eyes before you do something ... then you'll probably die along with your family.