conversion to MP3 files and USB signals

Well, it depends how much you want to spend. The truth is, if you download (for free) or already have itunes, you have pretty good encoding but use at least 224 kbps. It really depends on what you want to do with the mp3s.

If you are just listening on your ipod is one thing. If you are a DJ who wants to play in a club or own a restaurant and want to play better quality music, then convert them at a higher bitrate.

Professional encoding costs money, and it is better. I am an accredited engineer and use Logic Pro for all my professional encoding. It is better. But for run of the mill, don't go crazy. You can check this link : http://csoulpro.com/About%20csoulpro.html

as for the usb, I don't know. I am interested though because I am designing some LED lighting powered by usb. I will let you know when I find out.

Also, importing CDs are easy with software, but if you have an analog signal from outside the computer, there is no real way to achieve high audio quality without buying QUALITY converters.

Again, it depends on what the end use of the music is and how much you really care.

Read a previous thread or This both have extensive info about conversion of audio to mp3.

& wikipedia has plenty to say about USB

I use Nero 7, it works for me completely for CDs, but there is even free software around (Audacity) that will take even an analog source, over the sound card to make MP3 files...... or whatever you want....

Then you can down load most MP3 players just using WinXP without any other software (generally speaking).....as the devices appear to be only a small disk drives to WinXP....

With earlier Windows versions, generally you need special drivers. I cannot therefore recommend anything other than XP (Professional is even better!) or later....

(And Vista needs to be a few years older first!!)

You also need to also explain you aims fully so that we can answer you exactly....is it a private or a business question should also be mentioned too....

If your final destination is an iPod, I would convert to MP4. It is a better format than MP3. Apple calls it AAC but your run of the mill MP3 player won't play it, so if that is a concern, go with a 256kb or higher MP3. My ears are 45 years old so I find it hard to tell the difference between a very high quality MP4 and a standard audio track--years of rock concerts, I suppose.