Reddit mentions of Year Zero

Not a shitty answer to a shitty question, but this was a pretty interesting book that dealt with that subject. His previous book, The Descent (which the movie was not based upon) is much, much better.

You've already read two of the better ones.

Try Brian Keene - The Rising and City of the Dead. - a different take on zombies but you may like it

Joe Mckinney - Dead City

J.L. Bourne - Day by Day Armegeddon - it's self published, but it's not bad

Jeff Long - Year Zero - sort of zombies, plus it's really good

This one has some cool short stories - The book of the Dead

And I haven't read this one yet so I can't recommend it:

Z. A. Recht - Plague of the Dead