Have you checked the sticky threads at the top of the
Recommended Resources forum?
There are sticky threads with crowd-sourced book recommendations for various age ranges, including:
-
Book recommendations: ages 9 - 12-
Book recommendations: age 13+These may provide a few ideas.

There is also a regular, non-sticky thread in Recommended Resources, with crowd-sourced
books for adults which may be of interest.
For grammar, a go-to source for many years was
The Elements of Style, by Strunk & White.
E.B. White was also the renowned author of children's books Stuart Little (1945) and Charlotte's Web (1952).