Brushing your baby's head everyday with a soft bristle brush or comb will keep the hair free of debris and prevent cradle cap from forming. If cradle cap does become a problem, rub warm coconut oil - available at a Pharmacy - into the scalp, leave overnight and then wash off gently in the morning. You may have to repeat this treatment to successfully clear the scalp. See: 4/ii Cleaning your baby/cradle cap for more information.
Most babies dislike having their hair washed because it means getting water in their eyes. One way round this is to wrap them in a large towel and hold them under your arm so that they are leaning backwards over a bowl of water.
Carefully scoop warm water up over the back of their head to rinse the hair, add baby shampoo, then rinse thoroughly. If your baby is too heavy, or simply hates the whole procedure, just sit him or her, wrapped firmly in a towel, on your lap, next to a washbasin. You can then sponge your baby's head gently with a rung out flannel. Add a tiny amount of shampoo or aqueous cream to make a lather and then rinse off carefully, making sure no water, or worse, soap, gets near your baby's eyes.
Never pour water over your baby's head. They won't like it and you could end up with a child who throws a tantrum every time a shampoo looks likely.