Hi! Congratulations!
It's definitely best to get one now. You'll be too busy later, anyway :)
I like the fairly basic one at Target, called the Comfort Select Dual by Evenflo. As long as you don't plan to pump a lot, it's just fine and costs about $30.
Some advice: most women who hope to breastfeed hear wrong advice from family, friends and, worst of all, doctors and nurses. I've heard bizarre things from pediatricians and doctors alike, such as "some babies just can't tolerate breastmilk" (maybe they can't tolerate the cauliflower or the dairy or the chocolate in the breastmilk, or they can't tolerate that Mom's got oversupply and the milk is too sugary, leading to gas and other tummy troubles. But babies are MADE to not only tolerate, but thrive, on breastmilk!). Or "your breasts will sag." They WON'T! Well, they might temporarily shortly after weaning, but they come right back. You just need to support them by using sensible bras.
Some people say that nursing hurts. Other than in the very beginning, for just a couple of seconds at the beginning of a session, it shouldn't hurt to nurse. Oh, since this is your second, it will cause more contractions, but this is a GOOD thing. It flattens your belly and helps you to heal much, much faster.
If it hurts, that just means that the baby's latch isn't right - usually, it means that the baby needs to have a great, big, open mouth, big as a yawn, before you gently but quickly latch baby on.
I could go on and on with tips and such. Basically, hold your newborn so his/her ear, shoulder and hip are aligned, make baby comfortable and offer your breast. You can squeeze it gently to flatten it (to make a "breast sandwich" parallel to your baby's mouth to help baby get a good mouthful), but, I say, other than that, let baby figure it out. When my daughter was born, the midwife essentially tried to force my breast into her mouth, and the poor thing found it very stressful. The midwife thought she wasn't opening her mouth wide enough. When I let my daughter just do what she wanted to do, she did it perfectly. You might find that your baby just takes in a little, but then from there opens wide and gets a good, large amount of breast, well beyond the nipple (which is what baby needs to nurse properly).
In other words, try not to micromanage your baby :) They're born to nurse. I DO highly recommend La Leche League's The Womanly Art of Breastfeeding, but take their detailed advice on the mechanics of it as great tips for just in case your baby has difficulty.
Do not expect it to come naturally. It really doesn't! It can be very frustrating and difficult, so be prepared by learning all that you can NOW. Once you get it, it's great, and so convenient (not to mention the pounds will fly off of you, no matter what and how much you eat!). And you might be one of the few lucky ones that just put their babies in their arms and watch them latch right on.
But most mothers, I've found, don't prepare in advance, and in the postpartum period, especially if there have been any complications, a C-section, siblings, etc., are too overwhelmed to do the necessary research and resolve whatever is causing the problem.
About complications, C-sections and so on: you will best prevent complications and the technology-driven cycle that leads to "augmentation" meds and eventually a C-section by going to the hospital as late in your labor as you can possibly manage. Doctors want to intervene way too much, and this only causes problems. These problems ultimately make nursing more difficult.
Be aware that pain medication like epidurals can keep a newborn drugged for days, because a newborn's liver is so immature and can't process things like ours can. So this makes establishing nursing very difficult (though not by any means impossible). If you try to go natural and get to the point where you just don't feel like you can take it, that is the point when it's almost better. It's also usually the point where waiting for the anesthesiologist and for the epidural to get in and so on isn't even worth it - if you just get through that point, you'll be pushing soon and it'll be almost over. At that point, when the epidural finally hits, it just slows down your labor, when you otherwise would be almost done.
You can also try hypnosis. At 30 weeks, you're just in time. Go to natalhypnotherapy.com. I used their CDs and my labor was a dream. If it's not enough for you, you can always opt for an epidural. But going natural is a super great way to help establish nursing. It's also great because you won't have drugs in your body that interfere with the natural hormone rushes that aid bonding and healing.
Anyway, get in touch with your local La Leche League volunteer leaders now, participate in the next monthly meeting (lots of expectant mothers attend), and program their phone numbers on your cell phone. They're free help, so use them! If you're having any problem whatsoever, they'll come right to your house and help you fix it. They're pure gold :)
Have fun! And good luck on everything.
L.