There are some director's cut episodes, but they are the last four (regular episodes, not the two, final episodes). They do explain the story a bit better and fill in some gaps. I don't think watching them first will give you any more of an understanding or a better experience though. It didn't for me. As for the movies, I have The End of Evangelion but not Rebirth or whatever it's called so i can't tell you what that's like in relation to the series. Just start at the start and work your way through and you'll be fine. Heck, if I managed it (and I wasn't even into anime at the time ) you can to.