hi, the space a movie take up is depend on their time and the quality of the picture.
most of the movie of mine are 600mb, high qualitys are 1.5 GB.
people copy their dvd movies to their hdd using a software called dvd ripping software.
it can help you to rip your DVD movies to a video format that your computer can play, such as MP4, H.264, AVI, MP3, WMV, WMA, flv, MKV, MPEG-1, MPEG-2, 3GP, 3GPP, VOB, DivX, Mov, RM, RMVB and so on.
it can also do many video editing works, such as trim, crop, merge and so on.
Free download it here:
Just have a try and i hope it will be helpful to you.