To tell if a certian fruit is
ripe, follow this node.
Apples and
Oranges are
omitted because they are easy to tell when ripe.
Peaches: 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 to ripen 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.
Pineapples: An old myth is that a pineapple is ripe if you can remove a leaf from the crown. This is untrue because pineapples are picked ripe and ready to eat, after approximately an 18-month growth period. The pineapple color varies with time of year, so color does not indicate ripeness. Look for plump fruit with a fresh aroma at the stem end and store at room temperature.
Avocados: A ripe avocado is relatively firm, but will yield to gentle pressure when held in the palm of the hand and squeezed. Color cannot always be trusted to determine whether or not an avocado is ripe. Indeed, the squeeze test is the most accurate.
Bananas: When a banana is yellow with brown spots, it is at its peak of ripeness and sweetest in flavor. There is a ripeness chart at this website
http://www.freshdelmonte.com/faq_banana_ripe.cfm. If you'd like to ripen a banana quicker, place them in a brown paper bag with an apple or tomato overnight. They will work together to speed each other's ripening.
Mangos: Pick up the mango and check the area around the stem. If it looks plump and round, the mango is ripe. Most mangos in the store aren't ripe. Ripen the mangos yourself at home by leaving at room temperature for a day or two.