Laugh, Smile, Fall, Giggle, be Sore, you know all of that. Here's my advice, mainly a reiteration of what others have said.
3. Love the edges! If you ride the board flat, you are essentially riding the fence between two feisty board edges. If you catch the wrong one, you'll get a little ass-whooping. However, if you narrow the edge that makes contact with the snow to one-at-a-time and make your turns from edge to edge you'll have control of the board.
2. Learn that you will need to point your board downhill. Too many people are afraid to point downhill because boards gain speed in that direction. However, it is necessary, even if for a quick second, to successfully complete a turn.
3. Learn to get comfortable with speed. Not blowing down the mountain speed, but the board needs speed. You need to go from point A to point B to make a turn and there is distance between those two points and the only to get there is by moving.
4. Get from greens to blues real quickly. Blues are slightly steeper, but as someone said greens are often too flat for snowboards. Also, greens tend to have more people on them that tend to get in your way. On greens, most people are newbies and can't maneuver around you. On blues, most people can see where you are and what you are doing and go around you. I'd be willing to bet that more collision accidents happen on greens than blues and blacks, if for no other reason than sheer numbers.
Traveling the States and Taking Pictures