There are many choices out there, but my preferred method uses two programs:
- DVDFab (free portion - called HDDecrypter - it also does Bluray)
- Handbrake
DVDFab is used to decrypt the DVD (strips off the copy protection), and then Handbrake is used to convert the decrypted files (DVDFab outputs to a directory of VOB files) into an MP4 file. Handbrake has several profiles for different types of outputs depending in the desired device. For my Nexus 7, I tend to stick to the "Android High" setting.
Once you have your MP4 file from Handbrake, it's a case of connecting the Nexus 7 to your computer using the USB cable and copying the file into the "Movies" directory (ignore the warning message that might pop up - something about unknown filetypes). The standard pre-installed video player will run the MP4 file fine. I tend to use MX Player (free app from the store) to play videos, as the controls are nicer, and it plays other filetypes too.
Hope that helps!
Rhyan