Look online for a free dvd ripper. you need to convert it from a dvd to an mp4. I had a free one on my computer (it was a trial, you could convert like 5 on the free trial) but I can't remember what it was, and I just had my computer revamped so its gone now. But I kow you can find on if you search it.
Its not illegal to make a copy of your own movie. Its if you start selling them thats the problem, or making mass copies. I put a bunch of our movies onto my iPod touch when we traveled for our adoption so we had something t owatch if we got bored while out of the country, and also for our new daughter to watch while we traveled on three planes and 14 hours of flights total.