Yeah, I would agree with that Nar. Children's book was poor wording. I should have said "a story for his children".
What would be helpful is a timeline of Tolkien's life, and what was happening around him, both on a wider social scale, and on a more personnal level. Anyway, I found this brief biography a bit helpful in placing his work into a time frame of the author's life.
http://www.tolkiensociety.org/tolkien/index.html