For Seniors: Preview Music, Video, or Audiobook from iPhone 4S
You might want to use your iPhone 4S to preview a song, video, or audiobook before you buy it from the iTunes Store. Assuming you've already set up an iTunes account, when you choose to buy an item it’s automatically charged to the credit card you have on record or against any allowance you have outstanding from an iTunes gift card.
If you like it, buying and downloading are then easy and quick.
Open iTunes and use any method to locate a selection you might want to buy.
Tap the item to see detailed information about it.
If you’re looking at a music selection, tap the track number or name of a selection to play a preview. For a movie or audiobook selection, tap the Preview button.
The iTunes Store offers several free selections, especially in the Podcast and iTunes U content categories (click the More button to find these categories). If you see one you want to try out, download it by tapping the button labeled Free and then tapping the Get Episode (or similarly named) button that appears.