Basically a peach without any fuzz and a sweeter, more intense flavor, really ripe nectarines don't transport well at all - if you find them at your farmer's market, you should snap them up immediately! They can basically be used wherever you would use a peach in desserts such as cobblers or pies. Find nectarines that feel soft to the touch and that are a combination of deep yellow and red colors. They shouldn't be mushy or too hard and green.