I recently read:
Earth Abides--George Stewart
Alas Babylon--Pat Frank
A Wrinkle in the Skin--John Christopher
They are all very good books IMO. Earth Abides has a couple of hiccups, like gas still being good for a bit too long than realistic...but is was still great. I could see that Stephen King borrowed heavily from this when writing "The Stand".
Alas Babylon is a bit better, but short. I would have loved to see it a couple hundred pages longer.
A Wrinkle in the Skin is an earthquake EOTWAWKI novel and well written. Slightly dated, but very good if a bit short also. Still in print, I bought my copy online.
Non-fiction I added "Survive" by Les Stroud and "Wildwood Wisdom" by Ellsworth Jaeger and would recommend both as practical and easy to understand 'how to' books in the field of woodcraft and survival.
"By failing to prepare, you are preparing to fail.”