Make sure you have at least the MATERIALS to BUILD an underground shelter, in the case of fallout affecting your area.
Expedient ("emergency") shelters can be built in a couple days, assuming you have 2 or more able-bodied people in your household.
More people will die from fallout than in the actual blast zones.
Those who die in the blast(s) will die instantaneously as they are incinerated.
Those who die in the outlying areas will die, very slowly, from radiation poisoning. Nausea, vomiting, hair falling out, weakness, etc. But the problem is, it's not just you. You will have to watch this happen to your wife, little children, etc. and they might not take it as "stoically" as you might.
And we Catholics can't take the "easy way out" and do something desperate like a murder-suicide. Non-Catholics would find that very tempting in a fallout scenario.
Like I said -- be prepared. Have some shovels, pickaxes, maybe some scrap lumber, nails, 5 gallon buckets (for water, sanitation), work gloves, an extra air filter or two, etc.
In general, it's a good idea to have "practical items" in your basement, garage, etc. You never know when you're going to need rope, netting, dust masks, etc.
Unfortunately, the stuff you want to collect is the stuff that smart people NEVER sell at garage sales. Christmas trees, halloween decorations, breadmakers, and old magazines aren't very useful for survival :)
That having been said, you CAN get lucky if you keep trying. I like to go to the large "subdivision-wide" garage sales.