I would start out by strongly suggesting you have actual print copies of books and not just electronic copies.
I would also recommend you have actual CDs of the music you like and actual DVDs of the movies you like.
For books, I'd suggest getting a wide variety, including lots of good novels that you like. Imagine when you and your family are hunkered down in your house for a long hard winter, no TV, no internet, no phones, no "entertainment". Books that entertain you and bring you to another world, will suddenly become very important to you then.
In addition, get knowledge reference books as well as children's teaching books. I keep two sets of very good readers to teach children how to read (I'm pretty good at the teaching kids to read thing), printed history books, encyclopedias, technical books.
You'll have plenty of advice on "tactical" books and "improvised weapons and tactics" books.
However I would suggest that in addition, you have even more books on basic long term survival, I'm not talking about how to survive for a week in the wilderness, I'm talking about reference books on farming, crops, animals, soil, medicine, human anatomy, herbal cures, Homeopathic remedies, housing construction, machine making, maintenance, carpentry and the like.
You'll also want to of course have plenty of copies of your chosen religious books as well as several copies of the books about the founding of our current country.