Earth Abides by George R. Stewart

Isherwood has been in the woods, literally, for months without seeing another human being.  After surviving a deadly rattlesnake bite, he decides to rejoin civilization.  However, when he gets to town, he finds everyone dead from a plague.  Somehow he has escaped this plague, but now his task is to survive the infrastructure failure.  Although this book was written in 1949, it is an excellent story about a post-apocalyptic world.  Once we survive the initial collapse of civilization, how do we rebuild?  I love the strategies for "prepping" and the challenge of rebuilding a moral civilization.