I had a better opinion of Lucifer's Hammer than JohnnyEgo. Yes, the tech is 80s but the thinking is timeless.

John Ringo has a series out called Black Tide Rising. It's a zombie apocalypse story by an author who hates zombie apocalypse stories but is well-versed in military tech (I believe he's good friends with fellow Baen author Larry Correia). Some good stuff in there thinking about how to arm up, how to organize a post-apocalyptic societal group, etc.