You BUY a DVD, then rip it and encode it. If you are asking were to get pirated movies, that is not allowed here and is pretty lame IMHO.
Also, if you use the Skyfire browser, you can watch full movies at
http://www.crackle.com
You can also rip the PURCHASED movies to your hard drive, and use Orb (
http://www.orb.com) to watch them.