It's not a hard task, but it is long and slightly tedious.
I noticed though, after two attempts at burning, that I was making what computer geeks call "frisbees".
A frisbee is an improperly burned CD/DVD that will not work.
Brasero displayed an error saying it could not eject the disc. It then asked me to eject the disc manually.
Not a problem, until you notice that no matter how many times you eject the disc, Brasero is still asking you to do so.
Then when you ultimately hit cancel, you have your frisbee, which gets flung into the trash can at a high rate of speed.
The problem may have to do with not using the root user account, or with the fact that Linux distributions use different directories for the media cd mount directory.
In either case, I found that making your own temp directory in /home/user is the solution, for now.
Remember, /home/user is different for everyone. Mine is /home/denny/.
So I made a directory in /home/denny/ called temp. Now I have a directory tree that looks like this: /home/denny/temp/.
Now when you fire up Brasero, in the second screen it will have an option for choosing the temp directory.
It will look something like this:
But we do NOT want that temporary files option to read /var/tmp or anything else besides the /home/user/temp directory we made earlier. For instance, on my Brasero I want it to read /home/denny/temp.
The last step is a strange one. If Brasero gives you the same error it gave me, that it could not open the CD tray, and no matter how many times you open and close the cd tray it still shows the error, then you will have to hit cancel.
Hitting that cancel button seems like the last thing you would ever want to do, but by changing the temp directory to the one you created in /home/user, you should still have a fully burnt and functional CD or DVD.
In other words your Frisbee making days should be over. :)