Obviously, the #1 thing you need for a baby (if you're nursing, otherwise formula). We were only planning on using paper diapers til his umbilical stump fell off, but that took 3 weeks! We had a box of newborn diapers, but they were too big, so we went through a couple boxes of preemie diapers. The brand makes a big difference. We loved Pampers! We didn't like Huggies. (Now we use paper at night, and use Luvs).
To go along with this, a changing table, or low dresser is needed. And waterproof changing pads. Those things are great!
We had several places for him to sleep: crib, bassinet, co-sleeper (and unknowingly, our bed). The bassinet and co-sleeper were borrowed from Aaron's cousin. I wasn't planning on using the bassinet, but that became an essential. We could put him in it and roll him where ever we were in the house. I loved it! He did not like the co-sleeper at all. He did/does like co-sleeping. I don't think we moved him to the crib til he was at least a month old. He's now in the crib 99% of the time, and occasionally in our bed (today, for example, he and I napped together).
(sponge bath, unhappy baby)
We bought a wash pod, which is kind of shaped like a narrow bucket. It says 0-6 months, but we didn't have much success with it until he could hold his head up. I really like it when I'm bathing him without help, I don't have to hold on to him, he's upright and submerged. Happy. We did use the kitchen sink a lot, and once he was a little older, we took/take baths with him.
Carrier
We've ended up with a few different carriers: Ergo, Moby wrap, Mei Tai, and a sling. The Ergo came with the highest recommendations (it was also the most expensive). With the Ergo, you need a newborn insert for when they're tiny (you can use a receiving blanket, but it doesn't work as well). I got too hot most of the time when he was little. Now I can wear it without the insert, and it's better. But I still prefer the Moby and Mei Tai. That will likely change as he gets heavier. The Moby is great, especially when they're tiny. It can be complicated to use at first, and takes a little practice. The Mei Tai is Aaron's favourite, (I don't have a picture of that). I think the sling in my least favourite, since I feel like he's the least secure in it. But it's the one I keep in the stroller, so it works when we're in a pinch.
Breastfeeding
It doesn't seem like there's a lot you'd need other than breasts, but there are things that help. A good pump is a huge help. I was lucky enough to get a hospital grade pump for the first three months. I had a Medela Symphony, and now I have a Medela... something in a tote bag. I pumped and stored like no one's business (all storage bags are the same as far as I can tell. Don't bother with the ones that attach directly to the pump; they're trouble). A cover is useful. I hardly ever use mine now, but in the beginning it was a necessity. Nursing pads are also a necessity. Finding a good brand is hard! (Especially if you wear mostly soft shell bras like I do). I like Lansinoh and Medela the best. They are a little more conical shape so they're less viable. Avent are also good, but are harder to find outside of a baby store. Other brands are really lumpy, and look weird under a shirt (unless you have a hard shell bra, then it doesn't matter). I also thought I'd like the washable ones, but no. They are very lumpy, and get damp/wet really quickly. No bueno. Also, while breastfeeding is still new, nipple cream is awesome. I like the stick on nipple soothers, but you have to wash your nipples before feeding, which, with a newborn, is often. So it's annoying. Most of the nipple cream is food safe, so no washing required! I don't actually wear nursing bras a lot, even though I have them. I wear a lot of the "genie bra" style bras, sort of like a softer sports bra. I also use Fenugreek to help with milk production. A boppy or pillow is handy too. I would have liked a nursing stool, but I never bought one.
A swing is good, Bertie likes a side to side swing better, we just have a normal, non-fancy swing. A play mat is used every day in our house. He loves that thing. We bought a cheapy one from Ikea. A white noise machine is great. A baby monitor is great! We weren't planning on getting one. But we were gifted a video camera monitor, and it is awesome! We used a lot of gas drops and gripe water in the early days.
