This is my simple procedure for backing up my DVD movies:

Examine the DVD:

dvdbackup -i /dev/sr0 -I

Create a full backup:

dvdbackup -i /dev/dvd -o ~ -M

Creating an ISO:

mkisofs -dvd-video -udf -o ~/dvd.iso ~/movie_name

Testing the newly created ISO:

mplayer dvd:// -dvd-device ~/dvd.iso