Need more info. Some file types are incompatible with the iPad.
You SHOULD be able to drag ripped movies to your iPad from iTunes, so there is something else going on here.
I'm a bit bothered when you say you don't want to buy movies. Please tell me these are not pirate downloads. (Don't be offended. Piracy is against iPF policy, so we like to be sure we are not giving advice on how to do it successfully.)
I use DVDFab8 to rip DVDs. It outputs to various formats including iPad and iPhone. I've never used Handbrake, but I've read here that it works well.
Sent from my iPad 4 HD mini