What shareware, etc. do I need to copy a standard DVD to my desktop,
and then back to a DVD. We are not talking Hollywood stuff here. This
is homeschooling DVD's that should have little to no copy protection.
When I stick in the DVD it shows two folders. One, is AUDIO_TS and has
nothing in it. The second is Video_TS that contains supposedly 7.9 Gig
worth of .vob and .bup files.
(1) Why does it show 7.9 gig if a DVD is only 5 gig or so.
(2) How do I do this with shareware, or as last resort commercial
software.

well, if this is a commercially produced dvd, it could be a double
layered dvd, which can contain about the amount of video you have
described. standard burnable dvds (dvd-r) can hold about 4.5 gigs, so
in order to copy the disc, it would require two dvds. If there is no
copy protection, you could probably copy the bup files and however
many .vob files will fit onto one dvd, and then copy all the bup files
and all the remaining .vob files onto another dvd. Each dvd should
have all of the smaller .vob files that are probably title sequences
or other video that should be present on each dvd.

I expect this would work in such a way that some scenes would be
viewable from one dvd and others would be visible on the other. If my
understanding is correct, the .bup files are responsible for creating
the titles and other miscellaneous stuff.

If you have trouble copying the .vob files onto your desktop, it is
likely because the dvd is copy protected with the content scrambling
system (CSS). There are tools that will decode this, but they are
illegal, even when used to do something that is entirely legal, such
as making a personal copy of a dvd you own. Furthermore, I do not know
if there are mac versions of this tool, though I would imagine there
are. All I know of is the windows version DeCSS.

I hope this is of some use.