1)
You will need a PC with a sound card, any recording equipment with
an "INPUT" slot, and a connection cable. Connect your PC
with your equipment (mini disc player, tape deck or whatever else that you may have).
Connect the "LINE OUT" slot of your PC sound card
with the input (or "VIDEO/AUX") slot of your equipment using a connection cable.
"LINE OUT" on your PC sound card is usually used for playback. It is the slot
where your PC speakers or headphones are plugged in.
You will need a connection cable and, possibly, adapters to connect PC to your equipment. Usually the following 2 kinds of plugs are used: "3.5mm jack" and "RCA phono plug". Find cable that you need in local shops that sell audio equipment. The price for the cable should be under 20$/€, and is usually around 3-5$/€.
(used in most standard sound cards and mini disc players)
(alternative to 3.5mm jack)
(used in usual sound cards)
2)
Test the connection: start the playback from your computer and start the recording to your equipment.
Use a playlist to play back several MP3 files in a specific order.
MP3s must be audible on your connected equipment. If you hear music, then your connection is OK.
Then, just continue recording with your equipment.
3)
Test your recorded medium and enjoy, if everything was made properly!