I'm pretty sure YouTube is going to re-encode you upload to whatever format(s) they use. So, you should probably just upload the highest-quality, least compressed format you have (if the website will accept it and if you don't mind the extra upload time).
QUOTE
I'm new here, but not to the audio world. What I'm looking to do, is to create a High Quality online music archive using Youtube, of some of my CDs.
If "my CDs" are CDs of yourself or your band and you own the copyright that's fine. If they are regular copyrighted CDs that you purchased, you are not allowed to publish or re-distribute the music and YouTube will either reject your upload or remove it when they figure-out you don't have the right to upload the music.