Get a program such as isharesoft DVD to iPhone converter. These programs convert you DVD format to iTunes format then you just drag them into iTunes under video. You can put a cover picture on the video under the info tab in iTunes, I find my covers on imdb.com
Of course, my first question is whether you have done any searching on the forum? There are numerous threads & posts on this topic that will at least address your initial questions; if not then post back here.
But just as a starter, take a look HERE - a long thread (which I was a poster) that may get you started - there seems to be no GREAT one-step solution to this process - good luck and please report back your experience - will definitely help others in view of the frequent request for this iPad service - :thumbs: