For the Xbox to read a CD, it has to be in the Xbox File System. The best way to do this is to make an ISO, an image of a CD, in the XFS and burn it to a CD. This works since the computer doesn't have to understand the information to burn it.
To do this, I like to use a program called xISO. First, you make a new folder somewhere on your hard drive. Now, put only the files you want on the CD in the folder. If xISO is in spanish, read the leeme.txt file. It tells you how to switch it, but xISO has to be unzipped. Start xISO, and click on "Tools". Now, click on "Make a xISO". Browse to the folder that you just made, and click "OK". Now, browse to where you want it to be stored, type in a name for it, and click "Save". When it is done, it should say, "Image created successfully". Now, just use your burning software to burn the xISO, and you're done. The Xbox reads CD-RWs better than CD-Rs, but some CD-Rs work.