My kids were too young to read when Daddy left; probably I should have found books to read to them but I didn't (and I don't think Daddy did either). I relied on translating the bits and pieces about 'how kids react to divorce' from the grownup books I was trying to force myself to read to help deal with a situation I didn't even want to admit existed : P.
THANK YOU, from the kids(!), that you don't let your emotions about the divorce show. My family and friends put up an astounding and courageous effort and did not demonize my kids' father despite them seeing no justification to avoid doing so--except that I insisted.
Instead of books, I ended up waiting out the situation a little--since our family was so young (6,4,2,and pregnant), there was only one little girl in the oldest's class who was also a child with separated parents, but the sad truth is divorce continues to hover around 50% and gradually we are adding family friends who are also divorced/separated, which gives the kids a sense of normality.
Hopefully the parents step up to the responsibility plate and keep the process focused on "what is best for the kids." That helped our separation be of relatively little (still enormous of course) impact to the kids. People often comment, even without knowing that they have separated parents, how happy the kids are ... so we did ok. It can be done alright.
(I cried almost nonstop for a year and a half, whenever the kids weren't looking and occasionally when they were. It can still turn out alright.)