I've benefited a ton so far from the practical knowledge other people have given me about newborns, so I'm going to pass on a few of the things that have worked for us so far. I'm not claiming any particular expertise or wisdom, nor claiming these are universal solutions. I'm just publishing what has worked for us in the hopes that someone, somewhere, sometime, finds it useful.
1. Things sporadically recommended you to take to the hospital that I totally agree with, the Dad edition: A really, really long book (may I suggest Neal Stephenson's Cryptonomicon?) so you don't get bored during the many interminable waits, and after the birth, when everyone else is sleeping. Lots of snacks. A bottle for water. Cell phone charger. Plenty of change for the vending machines. Clean socks, clean underwear. Deodorant. The hospital will be very focused on taking care of mom, but you're largely on your own.
2. Thing nobody tells you to take to the hospital: A brightly colored plastic three pocket portfolio to put important papers in. Your hospital room will be a total mess, and every available surface will get drinks set down on them at some point. The hospital will give you a folder filled with dozens of sheets of papers you don't care about and three or four that you absolutely don't want to lose or get coffee stains on, and it's nice to have a separate place for the important ones.
3. You will need a calendar. Christie and I haven't had a paper calendar in the house in years. We do everything with Google Calendars, since we're both at a desk all day. But she's going to be away from the laptop a lot in the future, and we've got a shitload of appointments these days. I was lucky to find a month by month organizer on a clearance shelf at Target, because no one else had calendars that included June, 2008 (or even July). Think ahead on this one.
4. TV trays. They're not expensive, and you never know which chair the baby's going to like to sleep in, or which one will be closest when you collapse into it from exhaustion. So it's nice to have a set of portable side tables that you can put anywhere.
5. Baby mittens. You can't cut her nails for a while, but they will be long enough for her to scratch herself (or you). Socks won't stay on her hands (or her feet, for that matter), so pick up a pack of baby mittens.
6. Swaddling cloths. Chipmunk loves to be swaddled, but most blankets are 36x36, which just isn't big enough, plus they're too warm for July. Gerber makes some 40x40 swaddling cloths that are just about right.
7. Caffeine. This is another tip for dads. In the last couple of months, you'll be tempted to double down on caffeine use as your partner's pregnancy makes it impossible for her to sleep and difficult for you. Don't. Things are only going to get worse, and you don't want your tolerance built up. I cut back to a single cup of green tea per day back in the sixth month, and didn't break that rule until Christie went into labor, at which point, I could get a really good boost out of comparatively little caffeine.
8. Help. People will offer to bring food, or to come help with the baby. Some of these people will not actually be helpful, as they will spend their entire visit complaining about their husband, or bring along a toddler that will set fire to your sofa, or second guess all your decisions and tell you how they never worried about such things, and their kids turned out just fine (while said kids are setting fire to your sofa). But a few of your friends and family will be rocks, and don't be too proud to accept their help.
9. Be patient with yourself. If you're a mom, you just pushed out a person, and you're not going to be in your right mind for a while. If you're partnered to a mom, you're running on low to no sleep and you're probably got some hormone issues yourself. Myself, I've noticed some mood swings that can only be explained by baby hormones. Christie calls these "papa bear moments" and they're not pretty.
10. Be patient with your partner. I'm sure I don't need to tell you this, but the miracle of birth isn't just the new baby, but that you both survived this experience and are able to function even a little bit. Be grateful.
11. One more for dads. Ask a nurse at the hospital to teach you how to change a diaper. She'll know some tricks you can benefit from. And then make changing diapers your thing right from the start. There are several reasons for this. For one thing, you'll get a ton of credit for it. Much more than you actually deserve. For another, while it's not the most glamorous job in the world, it's hugely important. And too many men put it off and put it off, and then the first diaper they ever have to deal with is nasty toxic sludge when mama and baby are both sick and the baby's been eating sweet potatoes. (I was in danger of this myself.) Diapers start with a nastiness level of zero and slowly ramp up. By starting with that very first diaper in the hospital, you're building an immunity.
Besides, men are supposed to be tough, right? So nut up and change that diaper!