Here’s my list in no particular order.
Plan on having someone come clean the house weekly after the baby comes, and if you can afford it, keep it up at least once a month long term. Your wife will sing your praises for years to come.
Do you plan to use paper or cloth diapers? We used paper for the first few months, then switched to cloth. Some people use a diaper service.
If you have other kids, you dad, need to take them out for some one-on-one time at least once a week. It will give your wife a break, and the kids will benefit too.
Buy baby laundry detergent such as Dreft if baby has rashes (check the grocery aisle).
Have you and your wife go to Baby’s R Us, or a similar place to see what you might like. Just start a list. Some people use changing tables, but I never did. I just used a towel on the floor.
If you’re going to paint the baby’s room, you might want to use low-odor paint.
Go to child birth classes with your wife.
Remember when your wife is in labor, she’s the “queen bee”. She calls the shots. Don’t crack jokes, unless she wants you to, etc.
When she’s around 6 months along, she might like a pregnancy girdle. I sure wanted one when I was carrying twins, but I couldn’t find one that fit.
When buying baby clothes, consider getting gowns with no legs. Either just a zipper, a draw string, or an elasticized bottom to it. These things are the best, and they don’t have to be as expensive as the brand in this link. http://www.green-daisies.com/by-style-sleep-sacks-c-38_43.html
Have her go to a La Leche League meeting. (A support group for breastfeeding mothers).