The American Academy of Pediatrics recommends exclusive breastfeeding.
The American Academy of Pediatrics reaffirms its recommendation of exclusive breastfeeding for about 6 months, followed by continued breastfeeding as complementary foods are introduced, with continuation of breastfeeding for 1 year or longer as mutually desired by mother and infant.
The World Health Organization has a load of information about breastfeeding.
This picture is floating around Facebook about the amount of milk a baby's stomach can hold. The idea is that bottle fed babies overeat because no one wants to make 1/2 ounce bottles.