Take care not to pick apples that are too soft. Apples should be crisp and firm. Storing your apples loosely in a refrigerator will increase their shelf life.
There are thousands of types of apples in america alone, choosing a better quality apple means you know what you're getting.
The most popular are Delicious (which is easy to digest), Golden Delicious, MacIntosh, Pippin, Granny Smith and Rome Beauties.