It it possible to convert DVDs to my iPad?

Handbrake is a great tool for ripping DVDs and otherwise converting video.

The legal question is probably beyond the scope of this forum, but if you own the dvd and are only ripping it for your own personal viewing, I wouldn't worry about it.

Django your profile indicates you are from the UK, so you presumably would be governed by the laws of that country. In the US the legal precedent for this sort of activity would be "The Betamax case", which established that Americans have the right under Fair Use to "time shift" TV shows to tape.

I've used Handbrake. It makes a hugely complex process much more manageable, but it's not perfect.