I got my nursing bras at Walmart. I can't remember what brand but they only have one kind. They're very comfy and they don't cost an arm and a leg (like some of the maternity stores and websites do). I went with my regular bra size.....even though my breasts were bigger after delivery, it wasn't really a big difference and I was still able to fit my old size. I actually went to DD's when I got pregnant and the one bra I have is too big, so I ended up going with regular D's, maybe the same would apply to you (I think they're made a little bigger). My daughter is 4 months old tomorrow and they're still going strong, in great shape and no signs of tearing or even much wear.

I had to wear Medela. They were great and I would recommended them for anyone. Just be careful buying right now and too soon after baby is born. I was a 34D before I got pregnant and a 36DD while pregnant. I had lost most of my baby weight by the time he was 3 months and was wearing a 32DDD, which is what I still wear now and my son is 10 months. Good luck and congrats!

I tried several and gave up as I found them really uncomfortable on my nipples.
I've been wearing seamfree crop tops from Primark (2 for 4) that are really stretchy and I just pull them down to feed. They don't give much support but I'm not doing much exercise! I was a 34B before and now wear the size 16-18. Conveniently they also do the same style as a seamfree camisole top so I'm going to move to those now the weather is a bit colder.

My advice would probably be not to splash out too much before hand and wait and see how your breasts are to start with.
Good luck with the breast feeding. It's hard work to start off with and may take a month or more to become easy - but then it's really convenient and just lovely!

Bravadodesigns.com - they are the best, and their customer service is awesome. They will help guide you as to what to get.

I agree with cherbear74, Bravado is the BEST bra ever. I only own one nursing bra and have worn it everyday since my little one was born. It's a sports bra style and the great thing about the one I own is it's a 38-40D/DD bra. I sleep in it as well, it wasn't too expensive and is well worth the money. I started off my pregnancy as a 34B, and by the time I delivered and my milk came in I was a 40DD. I highly recommend their bra, here is a link to the one I own.
http://www.bravadodesigns.com/product.asp?ID=2&area=US

are you sure thats your size? I thought i knew what size i was...was wearing a 36DD....recently went to a specialty store and got sized as a 32G. Way off. I bought one of their bras...yes $50, which for me is a whole lot to spend on a bra, but i dont want to take this bra off. I can wear it with my clothes and looks like im wearing a normal bra. Before that i was buying mine online from OneHanesPlace.com...would be able to spend $20 and sometimes they have buy one get one half off...they dont have my crazy size. Though I must agree...your size is going to change. I would buy one now and get sized in a couple months and buy a better one.

I got mine from justmysize.com - they were very affordable and comfortable.

for the liners, since I don't leak much, I finally went with some reusable kind - I think I got them at target 3 pairs for under $4 - saved me lots of money!