Ghanima: if your hospital/birthing center/whatever offers breastfeeding classes, TAKE THEM. Some moms & babies get it right away, but a lot don’t, and it’s got a bigger learning curve than you think.
At the hospital where I had J, many of the nurses are also Certified Lactation Consultants, so that was really helpful – see if that’s the case at your L&D. That was so great, because I could go back there when we had major issues (it also helps that we live really close to that hospital). If not, find a La Leche League chapter near you, and go to some of their meetings. If that’s not your thing (and, I admit, it wasn’t mine), at least use their website to find some Lactation Consultants in your area, and put their numbers by the phone. My local La Leche League also has a 24-hour helpline; see if yours does. That way, if you get home from the hospital and are having trouble breastfeeding, your partner can say, “Here, honey, let me call the Lactaction Consultant for you,” instead of “Here, honey, let me make the baby a bottle.” Sometimes, that kind of support makes a huge difference!
Also, remember that it doesn’t have to be all-or-nothing; if you have a hard time getting started with breastfeeding, that doesn’t mean that you can’t do it at all and your baby has to have only formula. You can pump and bottle-feed, or nurse as you can and supplement with formula. That said, it’s worth it to give breastfeeding the best chance you can. If you can, try to find out in advance how pro-breastfeeding your L&D is; it can help to know if you’ll be getting lots of BF support or not.
Four nursing-related things to buy before you have your baby: a nursing bra (only get one beforehand, because you don’t know yet what sort of size you’ll be when you’re no longer pregnant – they sell decent but cheap ones at Motherhood Maternity, if you can stomach their awful return policies), a Boppy or other breastfeeding pillow, some disposable breast pads (you can get non-disposable ones later, if you need them), and some Lansinoh or other lanolin nipple cream (but NOT Mommy’s Bliss Nipple Cream, because the FDA recently released warnings about that one).
A couple of other helpful things to know: newborns eat every 2-3 hours on average, from beginning of nursing session to the beginning of the next one. And some babies will take an hour each session. So you might want to stock up on books or DVDs! When they’re hungry, most babies’ cries sound like, “mmmmm! mmmmm!” more than “waaa! waaa!” so if you hear cries with an M sound, try sticking your boob in his/her mouth. 
Two other products that I found/find helpful: an Itzbeen Timer , because you will have no brain once that baby arrives. It helps you keep track of how long it’s been since you changed the baby, fed the baby, how long he’s been asleep, whatever. It’s great! Especially in the middle of the night . The other thing is a website that lets you track your baby’s everything: sleeping, eating, diapers, bottles, whatever. It’s Trixie Tracker , and it can help you see patterns that you might not have noticed otherwise. I’d be happy to go on at length about both of these if anyone wants. 
Oh, and for before you even get to nursing, there’s a FABULOUS book about labor that I have to recommend: The Big Book of Birth . It’s very detailed and very positive, and I was so glad it came out before I had my baby!