Lots of good advice in this thread. I'll add one more thing. Being a father
is a multifaceted job and the roles/responsibilities can vary based on--to use Al Groh's favorite word--circumstances. Be the father your family needs you to be.
You undoubtedly have friends who are fathers who change just as many (or more diapers) than their wives, get up at all hours of the night with the baby, etc. You probably have other friends that, from the outside, do not seem to do their share. The tendency is to automatically think of the latter group as uninterested, lazy, or worse. Often, it is simply a result of the jobs each parent has and other circumstances in that house, as well as the talents and strengths of each parent.
I am 34 years old, and my father is my best friend. He has been for years. My friends are often jealous of the relationship we have now and had when I was growing up. That said, I can almost guarantee he changed less than ten diapers and that my mom was the one getting up in the middle of the night.
All of that is a long-winded way of saying--be present, be interested, be loving, but don't feel like you have to meet anyone else's image of what a father is or should be.