CS Lewis wrote two seminal books on the subject...The Problem of Pain and A Grief Observed. The second is essentially a collection of his notes following the death of his one true love...Joy Gresham, who like his mother died of a horrible cancer. A cynic need not even pick them up to easily dismiss his works as rationalizations within a Christian context, but I'd invite anybody who cares to be intellectually honest about the matter to at least take a look at them. If you'd care to peruse them, Chapter 1 of "A Grief Observed" is available here.
I observe grief everyday, first hand. I don’t need a book.