WMP9 and 10 wil organise your MP3s like no other, if you let it rip them from your CDs. It will create complete ID tags, organise folders by artist, then subfolders within with albums, and include album cover jpg in the folder.
The quality of MP3 rips are damn good as well, and it does it so damn fast too. I'm about to re-rip all my CDs via WMP10, since I just have a messy folder full of MP3s.