MP3 files do take up a lot less space than CD audio.
Normally MP3 files are created at 128kbps. Don't worry about what that means indetail yet. Just know that the higher the number the better the quality of the MP3 file.
160kbps is better than 128 and 240 is better still etc...
Naturally the higher the quality of the MP3 file the more space it takes up.
Even using 320kbps they are a lot smaller then CD audio.
128kbps is supposed to be the same quality as CD but in actual fact it falls far short of CD quality.
However for use with a portable MP3 player or a CD/MP3 player etc... it makes not a jot of difference so don't worry about it.
If you are going to run side by side comparisons with top quality gear then yes, you will easily hear the difference but at work, while you're not concentrating on it and either chatting or working then the liklihood of anyone being able to tell the difference is practically nil.
So, 128kbps is fine.
As for size...
Well a CD audio file is 10 megabytes per minute roughly.
An MP3 file at 128kbps is 1 megabytes per minute roughly.
So MP3 files are only one tenth the size of a CD audio file.
So on a CD you can get 10 albums instead of one. Depends on the songs naturally but you get the picture.
As for converting your songe into MP3 files...
Well honestly it couldn't be easier.
You need some software to do it for you. You have XP so you already have the software built into Windows.
Windows media player will let you put a normal music CD into the drive and then rip (this means convert or copy to...) MP3 files that are then stored on your hard drive in the computer.
So basically you can spend an hour feeding CD after CD into your PC and ripping them onto your drive.
When you get bored or you have finished you will have the start of an MP3 library.
You can play the songs/albums etc... that you have ripped through the PC while you write letters or play games etc... Saves you having to swap CDs etc...
Basically the same thing you want to do in work.
So how do you get the files into work where you have no PC ?
Well you need a CD burner in your PC to do that. A CDR/RW drive.
What you do is call up your CD burning software (Nero, Easy CD Creator etc...) and tell it to put the MP3 files you select from your library (wherever you told Windows media player to store them) onto a new, blank CD. It will tell you if the disk is full but as guide you should be getting 8 to 10 full albums on a single blank CD. Maybe a lot more depending on the type of music you like.
I like metal and some songs are very long so I only get 4/5 albums on a disk sometimes but I can get 20 albums by The Beatles on a single disk because they have short 2 and 3 minute songs.
So you get your burning software to burn you a disk full of MP3 files.
Now the last thing you want to do is stuff this new disk into a normal CD player. You can only put it into a CD player that can also read MP3 tracks.
And you already have one of those.
When you put the disk in it will take a second or so to be recognised and then (if it has a clever display) it will show you the title of the song your playing when you press the play button.
The CD player will just keep playing the songs on the disk until it's done in exactly the same way as a normal CD would be played.
The diffference is that you have 10 albums one one disk and don't have to mess about changing disks every five minutes.