This is very comprehensive. Thank goodness there is a comprehensive index, becuase the arrangement is a bit off-putting.
The chapters are broken down "chronologically" - The Thirteenth Month, The 25th to 27th Month etc etc.
Within each section it contains "milestones" type information - carefully labelled 'what your child MIGHT be doing' (it reinforces that children develop at different rates, but it still does encourage you to compare 'your child' with some 'norm'.
After that there are sections on 'What You May Be Concerned About' - for example, at the 19th month it might be 'night wandering, 'underactivity' or 'unclear speech' amongst other things. Thing is, these are not necessarily chronologically-linked. So you need to read right through the Table of Contents and use the index (some page refs are wrong, by the way)to find the topic you are interested in. Then follow sections on 'What You Need To Know' and 'What Your Child Needs To Know', again int he age-specific sections.
I think it would be much better arranged thematically. Perhaps a short section on things that really are age-specific. There are subsequent sections on things such as special needs children, toilet learning, feeding.
I have found the information on illness particularly useful and at other times much other information useful, interesting or reassurring.
I think this book earns its place in a parent's reference library. Its usefulness extends well beyond the toddler years, and for some things is still good in the early years of school (by which time life is so busy there isn't a lot of time for consulting books!)