Congratulations Marine! There's already been a ton of good advice given so I'll just second a couple of ideas that have been floated.

First - "Hand me downs" or second hand stuff. Big definite. Baby stuff is way pricey at best and outlasts 2 or 3 kids.

Second - The combo car seat/carrier/stroller. Used one for both of my kids. The convenience factor alone makes this worthy of consideration.

Pack a clean shirt for yourself in the diaper bag. No matter how carefully you place a burp rag the kid will find a way around it eventually.

Attend all doctor's visits with your wife. They're informative, fun, and show you care

Being a new dad can be intimidating and challenging but overall it's easier than bootcamp, it's even more rewarding, and the title lasts just as long.

Semper Fi,

Ed