First, you just need to make sure that your DVD's and home movies are added to your iTunes, and then you tell iTunes to sync them to the TV. Just like an iPod.
How do i put my photos and DVD movies and home movies on the Apple TV HD?
You cannot add DVDs to iTunes.
Apparently you were so eager to make your snarky comment you failed to read the second part of my post.
"If you are asking HOW to convert your DVD's into something iTunes can handle, there are plenty of other threads that already cover that."