As John points out, DVD-Video is not the format for what you want to do,with exactly what you have (see next paragraph). The closest that you can do would be to add the DOC's in a DVD ROM folder, and allow a user on a computer to access those via the necessary programs. For this, I'd make sure to point out the existance of the ROM material on the disc, on the packaging, and probably with an instructional Title in the DVD-content part of the disc.
One could do a series of AV files (in PrPro, or another NLE), where the DOC's would appear as Titles. One could then link to these from Menus. They would be "motion" files, but would be comprised of static text Titles instead. Just think of your DOC's as a series of long Titles, like very long credits. I've done similar, and used Photoshop to create the static graphics of the text as .PSD's, which were Imported into PrPro, and then Exported to go to Encore.
Now, work was being done by Sonic on eDVD, but it was discontinued. Had that Project completed, it would likely have been able to do similar to what you want.
To get closer to what you state, I'd look into doing an interactive Flash project. This could be delivered on a DVD-Data disc. One could build in interactivity, but then playing the disc on a set-top player through a TV would not be possible, unless on had a set-top player that supported Flash from a DVD-Data.
Good luck,
Hunt
