There is a great tutorial site:
Basically, if these are files you already have, you could convert them and create DVD's using a variety of tools, like those listed above.
If you wish to rip DVD disks and then back them up, there is DVD Decrypter, DVD Shrink and also DVD43 if you need them.
I personally like to rip using DVD Decrypter to my local hard drive, usually in FILE mode, then use DVD Shrink to customize things and get them the way I want, and also if needed shrink a dual layer DVD to fit on a single disk, then I export to a VIDEO_TS folder and burn that DVD-Ready folder to a disk using Nero.
That DVD43 is a little driver that lets you remove copy protection on the fly from any DVD movie disk you insert into your system. It is updated frequently to handle new forms of copy protection, in case DVD Decrypter doesn't work on it.
Again, that site has some excellent tutorials on it.