I don't remember leaking at all while I was pregnant, but as soon as my son starting feeding from them - straight after birth - I leaked a bit everyday. Once my milk came in, about 3 days post birth, I leaked like mad, especially everytime my son cried or if I just got a bit warm. The bath especially made them run like crazy, which is a handy thing to remember if you ever get too big and uncomfortable or they become engorged, it can really release the pressure.
Don't worry about the breastfeeding, most women are able to do it, but sadly most give up before they've really established it. It is very hard in the first couple of weeks, your baby will feed probably every couple of hours and you will be totally exhausted, then add on the sore nipples that you will inevitably get, and it's a really testing time. The best advice is just to battle on and get through it. Persevere with it and you will soon be rewarded, once you get the latch right and your baby starts a good pattern of feeding it will settle down and become really natural but you have to be patient, it won't happen overnight! Good luck x