Good websites:
http://babycheapskate.blogspot.com
http://baby411.typepad.com/babybargains/
http://www.hdydi.com/ (for twins/multiples)
http://www.raising-twins.com/ (obviously for twins/multiples)
My first piece of advice is BORROW as much as you can!!! The "baby stage" is so short (although it seems like an eternity) that it's not worth spending TONS of money on bouncy seats, tubs, activity centers/baby gyms...etc.
Baby/Bouncy seats: I used the fisher-price infant to toddler rocker with all my boys and it is at the top of my list for a reason. Say you need to go to the bathroom (which you will, duh!) You don't want to always be laying the baby on the floor and you're not going to have bassinets all over your house. You'll put them in the seat. It also keeps them upright for after feeding. Considering most twins are born a bit early, many have issues with spitting up and indigestion. (Mine did for about 5 months) Keeping them somewhat upright all the time is KEY! Also, the boys slept in these seats in my bedroom for the first few weeks. I swaddled them up tight and put them in their seats right next to each other. Again, being upright is KEY. I don't think my boys slept in their cribs until they were about 6 weeks. I separated them around 12 weeks (into their own cribs, but right next to each other.) Okay, I think I made my point on the seats. (Carseats would work the same, but I hated that they had to lay on the straps in them and that just seemed uncomfortable.) I had 4 seats in my house...2 upstairs and 2 downstairs.
Boppy pillows: Great for nursing, but I recommend getting two (something you can easily borrow and just buy a new case for) When I couldn't tandem nurse (If I was home alone because it required help) I could nurse one using a boppy and prop the other baby up right next to me in another boppy and either feed him a bottle or talk with him and hold his hand... I liked having two boppy pillows, but I'm not sure if it's totally necessary.
Swings: Unless you will have help around the clock (and let’s be honest…who does!?!?) I would have 2 swings. (Again, something to borrow, if possible!) Also, keep tons of batteries on hand for them…you NEVER want to run out in the middle of the night (or in the middle of a double meltdown.) My mom has a swing at her house from when my boys were little. She would probably let you borrow it unless it’s already out. =)
Double stroller. You could get one that’s just a frame that the baby seats snap into or you could get the full-on gig that has two seats for once the babies outgrow their bucket seats. There are arguments for both. I went with the giant gig and we DO use it. Other’s prefer a side-by-side. Graco probably has the best selection of double strollers/accessories.
OTHER MUST-HAVES:
-bottles (more than you think you’ll need…depends if you nurse some)
-Pacifiers (get one package of a few kinds to see what they like…then STOCK UP!)
-Spit rags (TONS) Gerber flat cloth diapers work the best here
-2 pack-n-plays (you’ll need two and you’ll use them until the kids are 3, probably)
-Musical activity table (w/ detachable legs)
-Baby gym/activity mat with lights and music
-Miracle blankets or swaddle me’s for when they’re tiny and liked being wrapped (start w/ 4 of these…you can always get more)
-Bundle me (jj cole) carseat covers for cold weather
-White onesies (no need to even dress them up at home while you’re on maternity leave. You wont have time for cutesy outfits, except for photo shoots) I’d start with 12.
-HALO sleepsacs are great for when they’re done being swaddled but too young for blankets in the crib
-ALL PAJAMAS SHOULD ZIP UP! (no snaps…too hard in the middle of the night)
-Baby washcloths (softer than normal ones)
-Monitor (video is up to you…I never had one because I think I would have stayed up all night watching it, but I’m sort of crazy!)
-Safety stuff (go ahead and register for this now…gates, door things, cabinet locks. They’ll be crawling before you know it!)
-Ear thermometer (yes, just spend the money)
-2 sets of crib sheets for each bed or get ultimate crib sheets for easy-in-the-middle-of-the-night changes
-Rocker with ottoman for you to feed the babies in their room (don’t skimp here…you’ll spend HOURS here and will sleep here many nights) I have this one and I LOVE IT!
-Nightlights
-Humidifier (cool mist) **get one that holds lots of water so you don't have to fill it as much, also with a cleanable filter so you're not spending tons on new filters all the time...
Thing I never used (but it’s totally up to you):
Bottle warmer
Wipe warmer
Baby bjorn (until they have a double, don’t bother! good for singletons, though)
Mobiles above the crib (I had one but just for decoration...you can only have them up for about 4-5 months because as soon as they can grab it and pull it down onto themselves you have to take it down. Just not worth the money...)
Bumbo (borrow, but don’t buy)
Tummy time stuff (just lay them on a blanket for god’s sake or use the boppy)
Bottle sterilizer
Mittens (the newborn ones, not winter ones)
Diaper/wipe caddy (they’re cute but don’t hold enough crap! We still have a full-sized pack-n-play set up in our kitchen with all our diaper stuff in it, plus extra clothes, ointment, spit rags, etc)
Here’s what TONS of people will get you (so don’t worry about buying):
Shoes (which they’ll fit in for 2.2 seconds)
Hats
Clothes (especially for girls…people go NUTS for pink)
Books
Blankets
