If you are new to skiing or boarding (I hope not to offend anyone):

Acquire a park map, spend some time learning the runs you are likely to encounter and keep the map on you. Learn the color codes and insignia. One small lapse and you will find yourself on a black run instead of a green run. That is no small difference.

Getting out of bounds is tough to do. Refuse to take any neat looking shortcuts. Yes, there's sweet powder on the sides, but forget about it.

You are going to get warm then cold, then warm then cold. If the lift "breaks", you will get very cold. The wind will bite at your face - have goggles. A lot of people wear ear protection.

Have a cell phone. If in a party, carry walkies, also. Have a re-grouping plan. Keep in frequent contact with your party - know what runs they are on (some parks are large - some are huge). Sooner or later, someone will need to go back to the lodge or the vehicle. By the way, having to go back takes forever - try not to have to.

You will get thirsty - Camelbaks are awesome. You will get hungry - carry snacks.

Secure all items so you don't lose anything should you hit the surface ungracefully.

Everyone needs to have personal information and 'contact in case' information on them.

Have a great time!