How to burn data CD-R?

I am not sure that I understand your question.

If you mean, how can I back up some files by creating a data CD-R? If so, then:

- Insert a blank CD-R into your superdrive. You will get a pop up dialog about what to do with the blank CD-R. Click OK, which will mount an image of the CD-R onto your desktop.

- Copy and paste any files that you want to save onto the CD-R image.

- When finished, select BURN DISC under the EDIT menu of the Finder. Or you can right click on the CD-R image and select BURN DISC.

That's it.

 

you dont "mount" an optical drive, only the disks you put into them.
CD's, DVD's ect will mount when inserted, and Hard drives will when installed and formatted

 

Well, Disk Utility is only needed if you're burning iso files. All other data you just drag onto the disk icon and then hit "Burn."

 

If you already have a disk in the drive, opening DU should show it in the sidebar. Opening DU is like opening any other app, just dbl click on it's icon in the apps folder. Even better is to find DU in the apps folder, clik & hold on it's icon, and drag it to the dock. Once thats done, you only have to click on it once to open it!

You can also check your finder prefs, to see if you want the mounted disks to show up on the desktop and/or finder sidebar

And you can burn basic data files in the finder using drag & drop, but not ISO images......