Cubase does not have buring ability in it's self. First you must create a stereo mixdown. It can be created by going to the menu "File>Export>Audio" and selecting 16 bit / 44.1 kHz / Stereo Interleaved (these are the industrial standard settings for a red book CD). You Name the file, choose the location where you want the file saved (i.e. My Documents) and click the "Export" button. Now that you have your 16 bit / 44.1 kHz / Stereo file....you can burn it with your favorite burning program. [Suggested Burning/Mastering software: CD Architech ]
Instructional Videos on the Subject:
Creating a Stereo Mixdown in Cubase 4
