This was a reassuring, matter-of-fact, and generally accurate description of common traits and difficulties presented by kids of this age range. I read it as my son was about to turn two and found myself thinking, "Ah, so that WAS normal..." through much of it.
Some of the perspectives that other reviewers have found dated, I personally found refreshing and somewhat liberating - it provided a much-needed, chill attitude toward raising children that balances out some of the nitpicky, perfectionist parenting advice that's so prevalent these days. The attitude is more about "this is what it's like to live with a one-year-old, and how to cope" rather than "these are all the essential ways to behave perfectly to raise the happiest/smartest/healthiest child". (I'm full to the brim with those kinds of books and blogs, and care a lot about 'doing the right thing', but sometimes it's nice to be reminded that just letting children be as they are, existing freely and experiencing their daily lives as we go about our own business, is an important form of kindness and love as well.)
If it weren't for one particular chapter, I probably would have given it five stars. I study personality psychology, and I found the chapter splitting the children into different physical and personality types to be very faddish and inaccurate - not entirely without some kernels of truth, but also with much that would be misleading or even potentially harmful to parents without knowledge in this arena. I advise readers to skip it, or at least to read it lightheartedly for inspiration like you might a horoscope. I also found the Q&A section at the end to drag on a bit, but I remedied that by skipping around and just reading the letters that were applicable to my son (they've conveniently provided headings to indicate the matter discussed).
Overall I would say this is an entertaining, reassuring, and informative book with just a few flaws that kept it from being perfect.