Ps. I found the best thing for us was to work with the advice for a little while (in our case contented little baby book) until you figure out what works for you. Routine was key for us, but we figured out where we could be flexible and never followed her advice for solids, for example.
You don't need to take their word as gospel (especially if they don't even have kids - that would set off alarm bells for me too), but some of it can be helpful if you don't know where or how to start.
HTH