1)
You will need a CD burner for your PC and a decoder to convert MP3 format files to WAV format files. WAV is a standard PC format for non-compressed sound. You can burn audio discs with WAV files. Here is help on MP3->WAV decoding with CDex freeware..

2)
Burn an audio CD from WAV files using your CD-burning software.
Make an "Audio CD", not "Data CD"!
Don't forget to set the pause time between the tracks to "0" seconds (it's usually set to default 2 seconds).

3)
Test audio CD and enjoy, you now have an original piece of audio art if everything was made properly!

Audio CDs sourced from MP3s have nearly the same quality as original CDs.
You will not be able to hear much of difference anyway.