If you live in the US, you are mistaken. There is no "fair use" copying of an entire commercial DVD allowed in the US, and thus this forum (which follows US law) can't advise you on that. The laws are different in most other countries (like Canada, where I live -- have I mentioned its the true north strong and free?), but the forum obeys US law. Hopefully the US will get its act together copyright-and-consumer-wise one of these days.
I can say, however, that what you are looking for (a networked drive that serves media files) is called an NAS unit (stands for Network-Attached Storage). That should help you find the hardware part, anyway.