Peaches are sometimes called the Queen of Fruit. Handle fruit carefully because peaches bruise very easily and decay develops rapidly.
Select peaches with a creamy to gold undercolor that best indicates ripeness. The amount of red blush on fruit depends on the variety and is not always a sign of ripeness. Two other indicators of ripeness are a well-defined crease and a good fragrance. Select fruit that has begun to soften for immediate use. Firm ripe fruit can be held a few days at room temperature and ripened further. Never pick peaches with a green undercolor since they will not ripen well. They will shrivel, become flabby and never achieve a good flavor. 

Peaches should be held at 32-35 degrees F and high humidity. Fully ripened peaches should be refrigerated immediately and kept there until ready for consumption. Sound and mature but not overripe peaches can be expected to hold 1-2 weeks at 32-35 degrees F with little adverse effect. Peaches deteriorate rapidly when stored for periods longer than this.

To ripen peaches,  65-70 degrees F is best. There is no gain in sugar content once a peach is picked from a tree. Its ripening process consists primarily of softening, development of juiciness, and development of flavor. So the riper a peach is at harvest the more sugar it will contain. Remember, once a mature peach begins to ripen it never stops, but you can slow the rate of ripening by using low temperatures.

When prepping, wash peaches gently, peel, and remove pits. Handle carefully to avoid bruising.

Peaches are loaded with good nutrition. A medium size fresh peach is full of nutrients and contains only 38 calories. Fresh peaches are an excellent source of vitamin A and contain some calcium which is not common in fruit. Peaches also contain iron and are low in sodium.

Yield for peaches: 1 pound of fresh peaches = 3-4 medium sized peaches = 2 cups sliced peaches = 1-1/2 cups puree

1 bushel of fresh peaches will yield 18-24 quarts of canned peaches 

Here are some PEACHY sites:
http://www.dole5aday.com/encyclopedia/peaches/peaches_menu.html
http://www.calpeach.com/default.asp
http://caltreefruit.com/
http://www.angelfire.com/oh/adoptalabrador/peaches.html