We're occasionally asked to put DVDs online, when the original video files no longer exist to work from.
Usually we'd create the video file to put online by connecting our DVD player to a PC with Premiere Pro on, capturing the DVD with the Premiere Pro software and then exporting the video to the file format we want.
There is free software that can do the same thing in one step, without the need for expensive software like Premiere Pro. HandBrake is an example which is quite easy to use. I've used this to convert a one hour 40 minute DVD to MPEG, and it took my PC about 45 minutes to complete the task.
I tried the convertion with a few settings and not all worked (when I saved it as an .avi video, it was upside down), but it provides a solution without you spending any money.
For help with using the HandBrake software have a look at the links on it's Wikipedia page.