Go to a library and look up Weston Price and Sally Fallon and LaLeche League for best nutrition advice for your baby. A good web source also is Chris Kresser dot com. He's an excellent nutrition researcher and had a baby just this past year, so it is a big interest for him.
This is a rare event, be sure you and your wife fully enjoy it. All over the world people with little money have babies. All a baby really needs are close, loving parents for several years.