don't think you can do much now, it's all about what happens after the birth.
keep your baby close, skin to skin straight away. google breast crawl now. get baby latched on asap, within first half hour. then feed on demand. if you think you're feeding your baby too often you probably have it about right.
and feed lots during the night too (as far as I remember).
most of my problems at the beginning were due to baby not being latched on properly (despite all the midwives saying he was latched on perfect, and I was doing fine, and pain was normal ) baby was about 3 weeks old before I met a fab HV who showed me how to get baby to latch on 100% properly.
What you can do now, is go to a breastfeeding group before the birth and make sure you have expert support on hand when your baby is born - ie your group leader and the address of a local baby cafe or in-hospital lactation consultant's group.
If you are delivering in hospital, find out if they have side car cots. If they do, these are the best to have your baby close to you as if actually co-sleeping. It has been shown that mothers who use sidecar cots from birth also provide access to the breast more often (at night) hence your baby stimulates your breasts more often. Though they have access to the breast more often than babies other babies who are not, the quality and length of sleep for the mothers are the same.
Invest in one if you can for your home.
also visit the biological nurturing website and have a good read. (it isn't the most straightforward to navigate so you can miss some good leaflets and articles) It shows you that babies can self latch as good if not better than when the mother latches on the baby.
Dr Jack Newman's website has some fabulous videos on latching as well as helpful handouts from starting out right to toddlerhood.
Kellymom also has great articles for starting out/ early days and onward.
I agree with everything being said. Once baby is born co-sleep and let them feed as much as you can. The first few days is the pre-milk (very important for antibodies and goodness), then the milk come in from the baby sucking. If they don't suck enough the milk maybe delayed. I very much agree that you need support and you really should hook up with a support group. Latch-on correctly too. I didn't and it was a nightmare, ask for help with that one. Once baby is born nuts (almonds, brasil nuts ect) are meant to be very good for keeping milk flow good. Good luck with it and do try and stick with it its so rewarding once you get going!