I've talked before about entertainment, and books were one of the options mentioned. But books can be so much more than entertainment. I remember reading To Kill A Mockingbird when I was in grade 10. It was a powerful book, and had I read it when I was Scout's age, it would have had an even deeper impact on my life. I didn't read Lord of the Flies until after I graduated college, but had I read it in junior high, I would have been deeply impacted.
My point is, if you are a reader, like my family and I are, then that is something you can contribute to a post nuclear event world. Okay, so the chances of every copy of Huck Finn in the US being destroyed except yours in unlikely. But what if your copy is the only copy to have survived within 50 miles? You may not want to lend the book out, but if you stocked piled paper and pencils or pens, you could copy the book and it could be used in a small classroom. Schools and libraries will be at the bottom of the governments list of things to do (which is understandable), but after a few months, kids will need to have the routine of school back in their lives. Once everyday isn't a struggle to survive, a lot of adults will appreciate being able to relax for an hour and read a good book.
You shouldn't collect just any books for this. Collect the classics that people can enjoy reading (the Greek classics are not relaxing when you've spent most of the day farming, sowing, hunting, etc). Also try collecting some good mysteries, science fiction (although you may want to stay away from "end of the world" plots), and maybe some romance and westerns. You may want to have a collection a children's books for different ages (reading to a child does wonders to calm them down).
I also collect different military manuels. Books about training, survival, and defence could also be very important. One of the things I plan on doing is collecting science books that explain how to make wind and water turbines, solar panels, and other things that may need to be made after an Event.
You may want to buy math, history, and general science books to keep in case you need to home school your children, or the locals form a small school for their kids. It is important that kids keep learning; it will make their life seem more normal and they won't be as far behind once the schools are running again.
Even if you choose not to interact with people outside your family circle, having your junior high and high school age kids copy the books you've put in your collection can be a good learning exercise. Have them copy so many pages each day, then once they've copied the whole book, have them give an oral book report. If you have a chalk board or painted a wall with chalk paint, you can have your kids practice math problems.