Charlatan will be the best advisor on jet lag -- but I've done enough australia and trips to europe over the years - i'll offer up the simple stuff... once you get on the plane... Force your body to go to the time of where you will be.. if you board the plane at 7:00am, and it's 9:00pm there -- whatever your normal bed time is... get yourself to sleep then... the airlines are pretty good about closing the shades when it's supposed to be night time even if it's day light out... so you don't have to worry abouot a bright plane - but bring eyeshades and earplugs (some airlines give them out-- others dont the ones they give out are pretty crappy quality- bring your own.). and taking something like exceedrin pm to help you sleep isn't a bad idea. a neck pillow (I love brookstone's fluffy one) is also a nice thing to have annd helps for sleeping.
DRINK LOTS OF WATER on the plane and while you are young, use lots of moisturizer both on your hands and your face... the plane is very drying and i find it makes me look and feel tired than i am -- if i look dewy fresh, i can psych myself into not being as tired... Avoid booze on the plane (you can stick the free bottles in your bag
, and anything with lots of salt in it for the dehydration effect...
Dress in layers and wear comfortable shoes... you'll probably go from cold to warm-- so layers will help you out a lot..
If you aren't sleeping, get up and take a lap around the plane if they let you.. othewise do some in seat exercises.. (the inflight magazines usually have them listed)
have a blast and take lots and lots of pictures