All of these are from a friend in CA with twin boys (now 4) and a girl (now 1.5). I, obviously, don't have any experience with any of it, so I can't comment or debate the merits of her advice, but am hoping to glean whatever wisdom I can from others.
A Brief Dissertation on Changing Table/Diaper bag/Medicine Cabinet/Car:
Diaper Bag: I use the Skip Hop; it's utilitarian, not too big, and Ben doesn't mind it. It's lasted to kid #3. I'm guessing you will want a cuter bag.
Strollers: I like MacLaren and Zooper strollers for the portable type. I don't have a rec. for a single SUV or jogger. I wouldn't recommend the brand we used for the boys (Valco).
Car Seat: Britax, Britax, Britax. We used Marathons with the boys, they go up to 65 lbs. Leah is in a Roundabout because it fits into our car. You will probably want an infant seat (the type that clicks in and out); they are convenient, but heavy and some babies hate them (Isaac). If you go this route, get a used snap n go to wheel the infant seat around in. We used the Graco Snugride infant seat. We skipped that with Leah because we couldn't fit it into the car. So she went right into the Roundabout and did fine. And I used the sling a lot on outings.
By the way, keep your kiddo rear facing as long as the weight limit in the car seat allows. It is so much safer for the kiddo. Leah is still rear facing. Also, keep them in a 5 pt harness until they're 18.
Diapers, wipes, diaper ointment, lotion, hand sanitizer all within easy reach. (I have this in a basket next to the changing pad).
In a drawer: Baby nail clippers, thermometer, alcohol swabs & vaseline (to take temperatures), q-tips, aquaphor (for minor scratches, eczema patches on baby, etc.).
Optional: paper towels to lay down under baby for really messy situations and plastic bags for the same. (We actually don't use a diaper pail with Leah; wet dipes get put in the kitchen garbage pail, messy dipes get bagged and put in the outside garbage).
Diapers, small pack of wipes (come with a pop top), travel-size hand sanitizer, travel size handi-wipes, empty plastic bags (for yuck dipes), tiny first aid kit (Target), small diaper ointment, chapstick, hand lotion or aquaphor, sunscreen (babies can't wear this until 6 months), small bottle infant tylenol (tip: dose the babies before their vaccinations; it's totally safe and helps)
Change of clothes (or at least a clean onesie or sleeper and keep extra clothes/dipes in the car).
Changing mat OR a small receiving blanket for changes on the go
Water bottle and snacks (for you!); bottle or sippy for baby; snacks for babies over 6 mos.
Teething toys/rattles/board books (later on)
Infant Tylenol (for first 6 months); Infant Motrin (6 months on--get the dye free kind); Pedialyte; Hylands teething tablets for later (homeopathic-tiny pills that melt in their mouths); neosporin (for scratches); 1% hydrocortisone (for rashes)
By EVERY sink in house: gentle hand soap, towels, hand sanitizer, hand lotion or aquaphor. (Your hands will get incredibly dry with all the washing, and with hormonal stuff. If hand lotion is not enough use aquaphor liberally. It really works.)
Tide Free and All Free and Clear are both good for laundry. Shout is good for stains. Keep the Shout wherever it's going to be remembered. I actually keep ours under the bathroom sink, because that's where I rinse out icky baby things.
In the car: extra dipes and wipes and changes of clothes; pop-up container of hand-wipes (for adults and toddlers)
A Brief Dissertation on Baby Hygene Products: I think it's safest to assume that you may have a baby with sensitive skin and/or allergies. I USED to like the California Babies Super Sensitive line of baby wash/shampoo (one product) and lotion. It's free of everything that might irritate a babies' skin (for example, if you have an allergy or sensitive baby, lots of products have nut oils or shea in them--big no-nos). The boys had cradle cap bad. We wound up having to use Neutragena T-Sal shampoo on their heads, plus hydrocortisone 1% ointment on their eyebrows on dr's recommendation later on to clear it up.
HOWEVER, Jake wound up reacting to the Calif. babies products. We now use the Walgreen's version of "All Clear" shampoo. It has nothing to react too, and leaves the kids' hair nice and soft. It's not "no tears" however.
We wash all the kids with Dove Sensitive skin bar soap. I use Aveeno Soothing Baby Lotion on Leah's very itchy dry skin liberally after bath. Eventually I will have to find non-reactive products for Miss Leah's curls. Once baby hits 6 months, I like the Coppertone babies sunscreen (in the pink bottle). It smells pefumey and has chemical sunscreens but it works on my kids (see below).
As for diaper ointment, I really like A&D (the old school clear kind in the gold and white tube). It smells distinctive, but goes on easily and makes a good non-drying/non-irritating barrier. I don't like the zinc based ones, because you have to work hard to wipe it off between changes, which I think irritates the skin. Also, Isaac and Leah are both sensitive to zinc (it makes them rash up, and they react to zinc based "natural" sunscreen; so much for nature being better than chemistry). If you wind up with diaper rash, try Boudreaux Butt Paste (available widely) or if it's a really bad case, Triple Paste (but only if there's no sensitivity to zinc).
Aquaphor is awesome for any dry or eczema patches on babies and parents (both Ben and I wound up with severely dry hands from all the hand washing). If babies have eczema, apply the aquaphor on their still wet skin after bath to lock the moisture in.
Hydrocortisone 1% is good to have on hand for random rashes.
A Brief Dissertation on Diapers: We used disposables. This is an area where you get what you pay for. The more expensive versions are more comfy for babies and work better. We used Pampers with the boys and Leah when she was small. Swaddlers until size 2-3, then Cruisers. I'm now using Huggies for Leah. Huggies overnights rock. Also, used (and still use) Pampers Sensitive wipes; they're thick, not too wet, and don't have any icky scent.
By the way, diapers can't really be too big as long as they are snug around the leg holes. They CAN be too small. If you start getting lots of leaks, it might be time to size up (no matter what the package says about weights).
Around here, Target is the cheapest for diapers. Especially if you clip coupons and save the coupons that are often included in the larger boxes of diapers. Costco (around here) only carries Huggies (which I didn't like with the boys).
A Brief Dissertation on Baby Wearing: Ergo rocks. Though I haven't figured out how to get Leah on my back, so I still do the front carry with her (which she barely tolerates now). I don't think the infant insert is worth it though. We only used it a couple of times. Instead, use a sling when they're tiny. The kangaroo cozy is good, though it's fleece and that won't work for your due date. However, I can also recommend the peanut shell sling which worked for baby and I until about 4 months; it's a tighter fitting one, so it might work for you, too, and it comes in lots of fun patterns. Many moms love the Moby wrap. That might work well for you since it's entirely adjustable. If you can try these on ahead of time, you have plenty of time to seek them out used. Or, ask for the Ergo for a present (that's what I did).