If you're thinking of buying the books: don't. If you have: throw them away. Any expecting or new parent knows exactly to which books I refer. Your baby is not a weekend away in Paris requiring a guidebook or a new Golf complete with user manual. Your baby is your child and the best way to learn parenting is by being a parent, not slavishly following rules set down by someone who has never met you or your baby or even, in some cases, had a baby of their own.
Of course you will want advice, guidance and reassurance but that is what your parents, friends and relations are for. They do know you and they know, or will be getting to know, your baby. They are there for imparting wisdom, sharing experience and pooling information not for the imposition of a one size fits all regime.
This is no Brexitish denunciation of experts but an assurance that there is not and never will be any greater expert on your child than you its parent. My particular bugbear with these books is that their ostensible purpose is improving the lot of new parents when in reality they do nothing but engender absolutely toxic feelings of guilt when, unsurprisingly, your child 'fails' to respond exactly as described in the 7 day plan that you must follow or catastrophe will ensue. I say parents but in truth this does seem to be a downside of parenting that seems to assail mothers much more than fathers. After all nobody and nothing will ever persuade me I am a bad mother.
I am no expert but I know that routine is good, however I also know that I get grumpy if I don't eat when hungry and don't sleep when tired. If I move to a new house, school or job it takes time to work out a routine. A baby is starting a new life so don't be surprised or dismayed if finding a workable routine is a matter of trial and error.
That is parenting in a nutshell: a lifetime or trial and error. And if you are trying you must never, ever feel guilty. You will get things wrong and your child will know you get things wrong and through that they will learn what it is to be human. Getting things wrong does not include failing to give your toddler an exclusive diet of organic, home pureed vegetables. Getting things wrong means exposing your children to experiences that they should be protected from and denying them experiences that will enrich them. The complexity of parenting is that sometimes those can be one and the same experience.
But even then it is of supreme importance that you should parent without guilt. Guilt wracks without benefit. There is a place for guilt and that is when harm has been deliberately caused. If your friends make you feel guilty when you are doing your best they are not your friends. If the 'wisdom' of books makes you feel guilty when you are doing your best they are not wise.