Hello Polly Wolly, best of luck with your second, and congratulations!
Somebody should have told you by now that milk doesn't come in until (usually) about three to five days after birth. Until then, you are providing colostrum, which is just what your baby needs most at this time, and which is crucial to developing a strong immune system. So you don't have to do anything, except encouage your baby to nurse as often as they want (I offered the breast whenever one of my lads woke, and any time they so much as murmured). Babies know what they need, and as another poster pointed out, once they have plenty of wet and dirty nappies, you know they are getting enough.
Which gets to your third question, yes, as I said, I would encourage baby to suckle often for so many reasons:
-Practice makes perfect
-the more they suck, the more milk you produce (and the less they suck, the lower your supply)
-the more they suck, the more happy hormones you produce
-every time you hold and nurse your baby you are bonding, comforting, mothering
The La Leche League (LLL) can be very helpful, although some people can find some of us pro breast feeders overzealous. I would just hate for you and you baby to miss out on this. Do as much reading as you can; I strongly recommend The Complete Book of Breastfeeding, put out by LLL.
ANY questions once you get started, post them here or get a good breast-feeding councellor. Remember,, for every Breast-feeding problem there is nearly always a breast-feeding solution, and once you get going, it makes life soooo much easier when you can feed yourr baby anytime, anywhere.
Best of luck to you!