I don't think I've ever encountered halakhot that pertain to interacting with newborns, but as any new parent knows, such interactions take up a great deal of one's time, during the day, at night, over the week and on Shabbat.
Are there halakhot that concern how to raise one's children from so young an age? How should one dress them, clean them and change them? When and where is it especially propitious to interact with them, what things might it be good to show them or to let them hear, when might it be advisable to not interact with them, and what sorts of things shouldn't they see or hear?
If there are halakhot of this nature, what are they and where are they recorded? And if this is something that halakhic sources don't touch on, why not? They seem to deal with just about everything else, and this strikes me as a fairly large subject.