I am not sure how this would work with a whole long DVD (mine was only a few minutes), but I did a looot of research on the internet before I finally decided to buy some video editing software that seemed very easy to deal with, practical, versatile and user friendly. (I found the software provided by Windows impossible to understand) I got Ulead video studio from Corel, which can upload, cut, edit, convert and save/share all kinds of videos, from your digital video camera, from a DVD, from your hard disk, music from i-tunes and other saved music files to use for background music in your videos and cut that too...
So, i guess, with a DVD, you would have to play in the DVD, get to the place which you want to make a clip from, mark the beginning and the end, cut that, delete the rest and just save this (mpeg-4 is the smallest format) I tried playing a video from my camera into video studio in AVI format, and pretty quickly the memory fo the computer was full, but in mpeg it worked.
Video studio costs about 120 dollars.
Uploading to youtube is easy once you got the clip saved in my documents (make a special folder for video studio files) , the instructions how to do it can be found in youtube help. but the clips have to be less than 10 minutes and below 100Mb. In mpeg-4 10 minutes is still only 50Mb or so.
Hope this helps.
If you get this program, you can contact me privately to exchange experiences how to work with it. My first clip took me all night, because I had to figure the technicalities, now I can do it in a few minutes.

That was my experience, but I finally found one that would allow me to designate the 10 minutes clip I wanted and that's the one I used to cut out the two vids I posted above.

ali