Suitability comments: As individuals, we have differing filters through which we view suitability
of literature. I've grouped books based on my personal
full or partial reading, YMMV (your mileage may vary :o). The older
the age level recommended, the more possibility there could be content
less acceptable to your personal values. Previewing all literature
before handing to your children for unsupervised reading is of course
recommended.
Some are better quality than others, but all have value in my opinion. Out of print books may be found from used book vendors. Some have beautiful artwork that increase the visual value.
Math
literature is not limited to computational content. Logic, problem
solving and abstract content occurs throughout literature without
appearing overtly math related, but this is invaluable for developing
mathematical thinking. See also related articles.