I used ripit which seemed to work quite well on my mac. It converts it to an itune friendly format which then syncs with ipad. You can download it as a free trial but you are limited to how many DVDs you can copy before you have to pay for the full version.
Mac-the-Ripper is the way to go.
It's a freebie and works very well. Make sure you select 'Main feature' to eliminate menus, extras etc.
Use Handbrake (another freebie) to change the ripped copy into the iPad / iphone friendly m4v format, this also keeps the size down.
It is a two part process but with very good results.
I'm afraid the above rather assumes you are using a mac, which you haven't stated. If you're on a PC I'll have to hand the baton over to someone else.