I only have a 2 hour flight, so I only bring my iPod and a book or magazine. But since you have such a long flight, I'd bring music, books, magazines, and anything else that would keep you entertained, like Suduko or a Gameboy or whatever.
And this was a couple years ago, but when I flew over to France, they had some pretty good and recent movies playing. I think you have a pretty good chance of a good movie playing when you're flying over. And if not, even a really bad movie will keep you entertained if you are desperate. Haha!
Definitely wear layers. Sometimes the airplanes are really cold sometimes they get really warm. So I'd wear a t-shirt and a hoodie and then a pair or jeans (or whatever). If it's cold, the hoodie will keep you warm. And if it gets hot, you can take the hoodie off and be comfy.