Listen to Corsair -- drink water until you feel like it's seeping out of your pores today. (If you're where you can read this.)

I have probs with altitude sickness and last time I went to the mountains (we were camping at 8,400 feet and driving up to 13,000) my doc prescribed Diamox. I'm not sure which worked best or if they both did, but I was fine.

Good luck and have a great time!