Hi:
You will need a program that will rip (convert) your CD's to MP3 files and put them on your hard drive. This will also make them considerably smaller in size without greatly affecting the quality.
There are several free programs available. A good one, in my opinion, is Musicmatch. There are two versions. A free one and a pay version. The free one is an excellent program although slower at ripping or burning (recording) then the pay version.
You can find Musicmatch at
http://www.musicmatch.com/
It will also act as a jukebox on your computer allowing you to play your files as you desire.
I hope this helps you and thanks for sharing.
Norm