This is an easy article that will tell you how to extract audio from downloaded youtube video offline flv to mp3 and put flv mp3 on ipod, following it you can enjoy the music on ipod with just simple steps.
go to YouTube http://www.youtube.com and find a video that you love. Copy the URL that in the Red box. Like this format: http://www.youtube.com/watch?v=sdUUx5FdySs
Paste your video file URL to Grab Video box of the FLV Downloader, it is a freeware, get flv url, then click download, you will get flv file on your coomputer