ADVICE!
The best thing I've found for avoiding jet lag is all about how you treat the days before and after travel and, naturally, the day of.
The day before: Really this applies more to the night before you hop on that plane but make sure you get a good night's sleep! 8-9 hours is recommended and try to do your best to not be stressed out while you're travelling because that in itself will wear you down.
The day of: Stress less, and get places early. Try to sleep on the plane but don't absolutely bank on being able to! When you finally arrive at your destination don't take that nap you've been dreaming of since the back of the customs line. Force yourself to stay up and moving until it is time to go to sleep locally. I would suggest doing some light exploring around town... nothing strenuous, just something vaguely active. You should definitely set an alarm for the morning!
The day after: Get up to that alarm no matter how much it hurts!! You'll do well if you make yourself move in the morning so plan on something more demanding and captivating-- if there is a hill, climb it but take things a little easier in the afternoon.
Your body is pretty adaptable if you force your internal clock to re-regulate through your activity levels. Pushing yourself the day you arrive will no doubt be the hardest part of the trip with, perhaps, the exception of returning home. The same basic steps are suggested for that despite the siren song of extra snuggle time with your own pillows (at last)!