Transfer from a cassette that you have a legal right to own and listen to for personal use. Traditionally, people have copied cassettes and shared them with friends and family with no legal implications. Refrain from distributing copies in mass quantities.
Create the CD for your own personal use. Legal issues arise with copying music onto a CD when you have not purchased the music and have downloaded if from your computer illegally. Never sell a copy of any digital music or electronic media which you have created.
Use facilities that have a cassette player patched into a CD burner or personal computer. Patch the left and right audio cables to the output plugs on the cassette player and the input plugs on the CD burner. The colored prongs should match at each end. A single cable patch can go directly into the cassette player's headphone. Start the CD burner and then the cassette player.
Alternatively, transfer directly from a cassette player to a mini-DV camera. Create a patch by connecting the audio cables from the output plugs of the cassette player to the input plugs of the mini-DV camera. Start the mini-DV or DV tape recorder on the camera first so you have a digital margin at the head of the tape before the music is recorded.
Otherwise, transfer without audio cables for an original analogue sound. Set up your cassette player and digital camera recorder in a sound design room with limited reverberation. Start the digital camera recorder and play the cassette to record it on a DV or mini-DV cassette. Import the digital video to your computer. Use Audacity to export the file, save it and burn it onto a CD.