Thank you Jennifer!
Basically I followed the default procedure: I dragged the files I wanted via "browse" over to the left-hand window, and continued to do so until I had accumulated all the folders containing the files I wanted to save. Then I did a simulate and as far as I could tell it was OK (I didn't have any indication to the opposite, anyway) so I went ahead and did the burn. That's about all there is to it.................................Sorry I can't be more technically "up among the leaders"