That's very exciting. I had a wonderful time on my flight to England. The flight back, not so good, but I was sad so.... I can't say that I can be of any help on what can/can't be taken on. I'm sure it sounds silly but I'm putting off knowing until right before I leave in November. I'm sure there will be lots of replies with good tips. Hopefully your plane will have the individual tvs in the back of the headrests. Being able to watch what you want, when you want is cool.
*edit* Ha!!! I remembered something! This tip is for before you ever get on the plane. Wear slip on shoes with no metal adornments. It'll save a lot of hassle during security check in. And it'll be easy to slip them off during the flight, if you wish, without freaking out whoever is next to you.
Good luck!