One of the easiest methods to do this is to use a website such as
www.video2mp3.net or www.youtube-mp3.org
These websites allow you to paste in the URL of the music you wish to download from YouTube, which you can easily find in the listing of the music on YouTube or you can just simply use the website address that will be visible on your internet screen. Once you copy and paste these in to one of these websites you then click the convert button. It should then take a few seconds for the website to convert the music from your chosen YouTube video into and mp3 file.
You will then be given the choice to download the music file, which should take between a couple seconds to a minute depending on the size of the file. Once the file is downloaded you can then find it in your media programme such as windows media player or iTunes, if it is not there straight away you may have to find the file and copy it into your library.
Once you have the file in your library it is just a matter of inserting a blank CD into your computer, placing the music you wish to burn into a burn list or playlist and then clicking the burn CD button in your media programme.
Other methods of burning music from YouTube onto a CD involve downloading Firefox and then downloading an add-on which allows you to convert YouTube videos to mp3, however the method listed above is the quickest and easiest way.