This would make a great article, but stretching it into book-length was a bit much. It is written for elementary school teachers (complete with lesson plans), but applicable to anyone who works with kids. Two things bugged me, though: 1) He spends 1/2 the book trying to convince readers that young children are capable of having philosophical discussions, but if you didn't already believe that, you probably wouldn't have picked up the book. 2) He constantly reassures teachers that they are capable of teaching philosophy, as if he assumes they will all be horribly intimidated by the prospect. Most of the elementary school teachers I know are very competent, confident individuals who aren't scared of the word "philosophy." It comes off as very condescending.
But, the book did make me more aware of my children's though processes, and was a good reminder to take their observations and questions seriously rather than just half listening while I'm trying to do something else.