The first month is a killer. Death of your sleep, your schedule, your uninterrupted time. To stop it from being the death of your marriage and your family, by all means take a month off from work. Sure you can put in the odd few hours per day, but in general, expectations should be a full-time one month of leave. This for the father. You really want to be there for a good amount of time, to see the new creature in all its poopy glory. Give baths, help feed (best is breastmilk in a bottle for dad feeding time), incessant diapering, and lots of burping and tummy time. Start to establish early the special relationship, which takes time and attention. Things will go easier later if this is done now. Take a month off (and reduced time for another few months, or longer, if possible).