Talk to your friends who just had babies about what it was like. Ask them to be candid. Some good friends of ours gave us a real shock to the system when they described the first couple of weeks as DW nursing, eating, and sleeping and DH doing everything else--diapers, swaddling, shushing, food prep, laundry, etc. (Our friend had a really rough birth.) We were like, "Whoa." And then I had a c-section and a huge baby, and so we were glad for that advice.
Take some walks and talk about how you might deal with things like night wake-ups. Read the early sections of Baby 411 or another book that spells out how many feedings and diaper changes there are every day/week so you have a sense. Take a babycare class together. Plot together, as a team, about preparations, gear, the pediatrician, daycare, how much time your spouse will take off when the baby is born, visitors...and a little more broadly, have some relaxed conversations about things you did and didn't like about your childhoods.
And someone mentioned date nights...we have actually been surprised at how much we want to spend time with our baby. We have been on two dates while our baby has been awake, once at 6 weeks when my mother was in town and once recently when we took a day off work and took the baby to daycare (a great suggestion from DCUM!). That felt more "normal" to us, didn't cost anything more than we normally pay in daycare, and we still had all the weekend with our baby.
Oh, and, give yourself some space to make mistakes and say stupid things without jumping all over the other person. The experience of being the one who gave birth and is home with the baby versus the one who watched their loved one give birth and had to go right back to work...they're both very intense in their own way and also very different. And it's hard to see the other person's point of view through the sleep-deprived fog. So, we recognized at the beginning that the other person would say something crazy-sounding to the other, and we allowed ourselves to point it out with a laugh. It helped defuse possible fights (though we definitely still had some!
Good luck!