For me, breastfeeding has been extremely easy. "Just do it," would be my first point of advice. Most articles that discuss breastfeeding are quick to make long lists of complications that can happen, from blocked ducts to mastitis, a low supply, or inverted nipples. Of course, it might be helpful to read about these things to prepare yourself but don't let that lead you to believe that the vast majority of women will have trouble breastfeeding, or pain. For many, it's as simple as putting their baby to the breast. Making sure you have a pediatrician who is supportive of breastfeeding can be of help, and interviewing pediatricians can be a good thing to do during pregnancy.
Also being aware of breastfeeding support groups and lactation consultants at your hospital can be of great assistance, should you need them. Breastfeeding on demand around the clock is the easiest way to establish a good milk supply and meet your baby's nutritional needs. Reading about the benefits of nursing on demand, rather than on schedule, is another good preparation for breastfeeding. And buy breast pads, because your breasts are extremely likely to leak milk all over your clothes during the day, and your clothes and bed at night. Some women find nursing bras handy, while others prefer regular bras for breastfeeding.