read a number of books mostly full of things that are common sense just worded differently.
the two most helpful things in hindsight so far (only 11 months in :-)) were the following a book around sleep  which is fairly short but can be shortened to a single excel spread sheet (which my wife and I did). the books seemed useless until we met others who had major challenges getting their child to sleep through the night, either we were super lucky or this book was amazing. ask me in a year after our second and I'll let you know if it was luck or not.
and then being told that once the kid comes out thousands of years of evolution magically hit you in the back of the head. this surprisingly was completely true (although I still do not know how)
lastly, none of my friends that live close have kids yet and some relationships have gotten weaker while others stronger. I think some of my friends are keeping distance for 'reasons' which is frustrating because losing touch with a good friend was not an expected result after having a kid.