Insert a blank dvd/cd, click "show in finder" or text similar to that in the little window you'll get (if you don't see this question asked check your system preferences). Then drag files to the blank dvd/cd in finder, click on it to select it, click burn. that's it. (from memory)
I'd try just using Disk Utility. Insert a DVD, click on the DVD (the one you just inserted, its in the list to the left), click File->New->New Image from disk1s0 or whatever it says. Save the image as whatever and make sure its DVD/CD Master (if that option is avail. its in a drop down). Then just burn that back.