The previous part is all well and good but what if you don't have warning, or are not within 2 minutes of your fall out shelter? Well, there are really only to outcomes to this: either you survive the blast, or you don't.
If caught unawares, the first clue of nuclear attack will be the whopping great flash of light which, if you're facing the blast, will blind you (possibly permanently). This will be followed by a sound wave which would rupture your eardrums if you're unlucky enough. And finally, if you still haven't realised, the third whopping great clue is the blast wave itself. This will be of immense magnitude, force and heat. Anyone within 0-30km of a 1 megaton blast will almost certainly die (either by being incinerated, vaporised, obliterated or through the effects of radiation poisoning (the effects of which we will cover at some point)).
If you're stuck in the middle of a field, you will either be far enough away from the blast to run for cover, or, you will die pretty soon. Yay, I guess? I mean, life after the bombs will become so unbearable that it throws the question of surviving into reasonable doubt, but hey, we're human.
If you happen to be within the protection of an historic house (stately home) like one of those belonging to the National Trust, you have a relatively high chance of surviving overall. The thick walls give good protection from the blast waves and heat, and the extensive cellar systems give sufficient protection from the radiation poisoning and the elements during a nuclear winter. You can't lose, in retrospect. Also, they'll make good hideouts from looters and a good base from which to start rebuilding civilisation.
All in all, be don't go anywhere too far out in times of trouble and if you do, always bring enough supplies to survive a few days without contact. Like most things, nuclear bombs are more common sense than anything else.
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I'm hoping to do the effects of radiation next and that's always fun, so stick around... please...