Download USB driver found at Samsung > Support > Samsung Admire SCH-R720 > Downloads & Manuals, etc.
Once installed on your laptop, connect your phone with the USB cable that came with the phone (it's also part of the wall charger).
Navigate to "notifications" on your phone's screen. You will see "USB connected". Click large button icon to activate mass storage setting which then allows your computer to "see" the phone's SD card as a connected storage device.
You can transfer music, etc. to the appropriate folders in the directory. When finished, tap the large button icon once more to turn off mass storage to safely disconnect the device.
Also: download the PDF manual found along with the driver. It is much more in depth than the literature included in the box.