Set up your turntable and plug it into a power outlet.
Connect the turntable to the preamplifier using the phono input on the preamplifier. Be sure to use the phono input, which will be labeled "Phono" on the preamplifier. Use a standard RCA or other audio cable to connect the white jack to the white jack and the red jack to the red jack. Ensure the settings have sound going to the line out jacks, if required. This can be completed on some preamplifiers by turning a selector switch to "Line Out" or depressing a "Line Out" button.
Plug the two-prong end of the audio cable into the back of the preamplifier using the line out jacks.
Plug the one-prong end of the audio cable into the back of the computer, into the line input jack for your computer. The line input jack is usually light blue. This jack will be either connected to the motherboard (near the mouse and keyboard connections) or on your sound card (with your other expansion cards).
Start your audio recording software on your computer and select the "line in" option for input. Depending on your software, this may be a setting that says, "Input Selection."
Start your record on the turntable and the software will start recording the audio. You can record the entire record at one time and store it in one file, or you can stop the record after each song and start recording another song, so each song is one file.