Must I toughen my nipples during pregnancy to breastfeed?

I read in a book that it's important to toughen your nipples during pregnancy to breastfeed. Is this so? What am I supposed to do?

This is really old advice. There is no need to prepare your breast to breast-feed. Some people worry about inverted nipples, ones that go in with stimulation rather than protrude. However, these nearly always become protruberant later on in pregnancy. There is no need for breast massage or wearing nipple shields. Some people worry about breast stimulation during pregnancy. The hormone that is released with breast stimulation also makes the uterus contract. However it only does so if the uterus is ready for labour. There is no evidence that nipple stimulation causes pre-term labour or miscarriage. Many antenatal classes have sessions on breast-feeding. The important advice for encouraging breast-feeding is as follows. Put the baby to the breast early after delivery, do not give bottles or fluid supplements and make sure that the baby has the whole nipple and surrounding areola in his mouth. Getting the baby to do this last thing may require help.