congrats! ours is 5 months and time has absolutely flown by! I
There's a lot of great advice here! here are some random tidbits, with a theme others have already mentioned- do what works for you, be protective of your time, and tell people to f off when you need to. You'd be amazed how many parents and grandparents expect you to entertain them so they can see the new baby. Ours were great, a lot of our friends had bad experiences. Try to keep the hordes at bay for a couple weeks and only allow nuclear family, so you can get a bit of sleep without worrying about needing to clean the toilet because cousins want to come over. Along these lines, don't care what your toilet looks like when you're caring for a newborn, you're got more pressing matters
In the first few months, you are the pit crew. Your job is to take care of mom. Both of you need to take care of baby, but you need to keep an eye on mom. No matter how tired you feel, she is more tired. Look for whatever opportunity you see to take things off her plate so she can eat, sleep, feed the baby and nothing else. The first 3 months are basically like the "33" pilot episode of Battlestar Galactica- it never stops, and the slow grind will wear you down. Prioritize what has
to get done and focus on that. If you can spend money to save time, do it, time is your most precious resource.
One thing I hadn't expected was that breastfeeding was an incredible source of frustration and anxiety- even more than we had read about. Most of the first time moms we know had an incredibly difficult time starting out- even the ones that ended up having a great experience went days/weeks on an emotional roller coaster while getting started. Basically you might want to plan for mom getting close to a breakdown, due to the combination of exhaustion, baby screaming but not successfully latching/feeding, bleeding nipples from baby improperly latching, and you as a dad feeling absolutely helpless as your wife convinces herself she cannot possibly do this. Most first-time moms go through this, and most get through it just fine, but while they're going through it, they feel like they're never going to get through it. She's already sleep-deprived, we had a hospital full of nurses and lactation consultants basically telling you you're a terrible parent if you're not breastfeeding, and there's so much of an undercurrent of expectations of what your wife thinks she needs to do, what's she's always imagined she would do, etc. My wife was the most emotionally distraught I've ever seen her during this process. Ultimately we decided to go with pumping, and supplementing with formula as my wife's milk never fully came in, had an especially terrible time latching, etc. The DAY we decided to supplement some formula took so much stress away, as the baby was full and happy, which has an amazing effect on mom & dad too. Could she have stuck it out? Probably. But she was miserable, and making that simple change had a profound effect for us. So yeah, find what works for you, don't care about what anyone else thinks (including grandma). If it's important to you, then do it, but don't let others second-guess what you've decided.
Stockpiling food in the freezer you can quickly reheat in the microwave is great- you will have days in those first few weeks when you simply cannot expend the energy to cook, as eating is something you only have time to do after baby is taken care of. So if you can, cook and freeze some food for the times when you're too tired to think
Free stuff: babies are a huge racket, and companies will pound down your door to give you free stuff. If you're registered at amazon, they'll send you a box of free stuff. Even if you don't intend to do a baby registry- make one anyway and don't tell anyone- you can buy it off your own registry- the act of having a registry will give you free stuff in the form of discounts when "completing the registry". So if you're gonna buy a stroller, put it in your registry at Babys R Us, then buy it, and you'll get a coupon for buying more crap. Formula companies will send you a hundred dollars of free food, and 20% off coupons for life (saves $20 a month), if you register on their site, etc.
Clothes: buy cheap stuff- your kid will outgrow them instantly, and they'll get stained immediately. See if your town has a second-hand store for baby clothes, lots do. Happily accept hand-me-downs. We never pay full price for any baby clothes- stuff is always on clearance at Carter's.com and the like- stock up on "staples" like onesies in sizes you'll need later when they go on sale- they're $20 new, but are often on sale for $5. You might be tempted to go all Steve Jobs on your baby. I floated the idea of just getting her 30 identical solid-white onesies since we'd be changing them often and we could easily bleach if they got nasty. I was, umm, politely overruled on this issue
ok, I'll stop! I'm happy for you, being a dad really will change you for the better.