Babies typically don't get very dirty. Wash with water only, adding soap every other bath. The soap should be mild, and perfume free. Many doctors recommend Dove Scent Free for Sensitive Skin. Pat your baby with a towel - don t rub.
Friction can cause irritation.
While your baby is still damp, apply a quality, perfume free lotion. Some examples of this would be Cetaphil lotion, or Eucerin. Many babies suffer from a condition called cradle cap. Cradle cap occurs when dry skin builds up on the scalp of a baby, and can result in large crusty patches usually on top of the head and on the soft spot. Unlike other dry skin problems, this usually requires scrubbing to remove.