In baby books like what to expect the first year goes all into detail in what to get besides I would get that book anyway cus when your awake at three in the morning because one thing or another it really helps. plus It goes into each month of life so if your read ahead you can be prepared for it. And I would purchase it now and start reading it now cus once the baby comes you wont have time to read!

You could also get:

Highchair

Nappies

Changing mat

Baby Moniter

Baby Gate

You can also get a baby bath which is much safer then bathing a normal bath and i find it very useful.

Playmat.

And Baby books like Justins1favmom said.

And take genevera's advie overstock.com is brilliant i have only just looked at it and i have ordered baby-gates and some lovely bedding and good prices.

I could not live without my boppy the first few weeks, it made nursing so much easier. My baby adores her papasan bouncy seat, and her little play mat with toys that hang over her ( she's 3 months old). We also use the high chair (reclined) already because she likes to be up where she can see us when we are eating dinner. I use a Medela Pump in Style dual breast pump. Its way better than a single manual pump. However, I wouldn't invest until she's nursed for a couple of weeks. They are quite expensive and if she ends up not sticking with breastfeeding then it won't really get used. Then again you are having twins so it might be wise to get it because she could pump and let you feed one while she nurses the other and alternate each feeding. Using a slow flow nipple on the bottles will help avoid nipple confusion because the baby still has to work to get the milk out. Oh and use Lansinoh wipes for the babies and nipple cream for Natalia. They are 2 of the single best items out there. The wipes are fantastic because they are super easy on a baby's sensitive skin, and the nipple cream is probably the one reason I am still nursing. I use it after every time I nurse and it even helped keep me from getting sore at the beginning. I use their breast pads, and milk storage bags too. I also love my cosleeper. Its a little crib that the side folds down on and it sits right up against your bed. It makes it so easy to access the baby at night but keep her safe at the same time. I'm sure I'll think of more, but that's a start.