well don't know anything abt sci-fi coz i think they're frooty.. but the closest thing to a sci-fi that i've read is "Alas Babylon" by Pat Frank.. its not really sci-fi but i thought it was pretty good. on the book, Russia nukes America and there are a few survivors and its about how they cope with the environment.. if you're not a gr8 fan of books, its a good one to start off.