Cftennant, I'll add something to what Posaune just said about boots.
When you try them on in the shop they should be difficult to get on your feet. Like, really difficult to wedge your foot inside. Once you get your feet in, you should feel the boot walls touching the far ends of your toes, touching your feet along both sides, and contacting your feet along their tops (as in, ceiling touches your foot). Your heels should not rise when you try to make them jiggle upwards inside the buckled boots, no matter what you do. The boots should feel tight, but they should not be cutting off circulation. All of this should happen without you needing to clamp down hard with the buckles.
If the rental boot comes with a shoe size attached to it, try one that is TWO sizes smaller than what you normally wear in street shoes. Force your foot into it, buckle up, stand around and see if after a few minutes it feels doable. If so, you're ready to go. If it hurts (as in painful) then go up a half size and try again. One size smaller than street shoes should be the smallest you go; choose that size only if there's pain after standing around and walking around for a while in the boot, because the foot may say No! at first then rethink; give it a chance.
Boots transfer your movements to the skis. You don't want any empty air inside those boots; no loose steering wheels, please. You'll have more fun if your boots are snug (as in, "tight" without pain), because your skis will do what you tell them to.
Enjoy your trip. I wish I were going, too.
Edited by LiquidFeet - 3/27/14 at 7:53pm