You can keep peaches and nectarines for one to three days but you have to be very careful, one small bruise and it will go bad on that spot. Firmness and days from bloom can also be used to estimate maturity. For more information on apricots and nectarines click here. To check for ripeness press gently near the stem end. If it yields slightly, it's ripe.
Pears are one of the unique kinds of fruits that ripen best off of the tree.
If allowed to ripen before they are harvested, their smooth, delicate flesh often becomes 'gritty'. If you have to ripen the fresh pears that you purchased put them in a fruit bowl or paper bag at room temperature. Not all pears turn yellow as they ripen. Aside from Bartletts, which turn from green to bright yellow, or Red Bartletts that change to a bright crimson color, most pears show little or no change in color as they ripen. Asian pears however, are similar to apples, and are harvested closer to physiological ripeness, and placed in cold storage.