Most sleep books are anecdotal and not research based. Dr.
Weissbluth explains why children need sleep, and what norms are
appropriate, and why it shouldn't be negotiable - similar to proper
food habits and the use of carseats. Contrary to some posts, he
doesn't say you have to let them cry it out, he explains different
methods of sleep training and why extinction crying is the easiest.
I believe he also notes that about 10% of children are outside of
the norms of sleep and may not follow his schedule.
We have referred to this time and again when it was time to
"retrain" our girls after interrupted sleep patterns. The trick
with this or any other book, is it use it with common sense and
adjust your approach as it fits your child.