There're different softwares for different computer.For PC users, you can use Cucusoft DVD Ripper Ultimate, which converts DVDs to play on almost any portable device including iPad, iPod, iPhone, iPod touch, iPod video nano, Zune, PSP, video-capable MP3 players, video-capable mobile phones, Pocket PC, etc.
And for Macbook users you can choose Mac DVD Ripper, a Powerful DVD ripper to rip DVD movie to AVI, MPEG, WMV, DivX, MP4, H.264/AVC, RM, MOV, 3GP, MP3, WMA, WAV, M4A, AAC, AC3 on Mac.