Download an audio recording-and-editing program. Professional audio engineers usually use "Pro Tools," but a free audio program, such as "Audacity" or "Acid Xpress," is adequate for sampling at home.
Install and configure your sound card or USB audio/MIDI interface according to the manufacturer's instructions. Be sure to install all drivers needed to run the device.
Install and configure your audio recording-and-editing program. To configure the audio for "Audacity," locate the "Edit" menu and choose the "Preferences" option. Under the "Audio I/O" tab, configure "Audacity" to recognize your sound card or audio/MIDI interface as the correct input and output for the program's sound.
Plug in your devices. Samples imported from an external audio-input device should be jacked into the microphone or audio-in jack on your sound card or audio recording device.
Test your audio input levels. Using the "Preferences" menu in "Audacity," play your audio input device and adjust its volume so that the volume indicator shows a good audio input level. (The volume bar is a colorful bar with green, yellow and red sections.)
Choose the beat you wish to sample. You can use beats from songs that are already on your computer, or you may decide to use a sound sample from a nondigital audio source, such as a record player or tape recorder.
Open "Audacity" and start a new project. Add a new audio track.
Load your audio into the program. Audio files from your computer can be imported using the Import function.
Record any nondigital samples from your record player or audio device. To begin recording a track, select the button with the red R to record-enable the track. Begin the recording by selecting the button with a red circle, which indicates you are ready to record, then the "Play" button, to set it in motion. You also must trigger playback on the audio device that you're recording. Stop recording when you have recorded the part you intend to sample.
Isolate the portion of audio you wish to use in the sample, using the editing tools in your audio program. Once you have isolated the sample, you can repeat it to create a loop, or you can export it to a beat-making program (such as "Acid," "Ableton" or "Reason") for processing into a completed beat.