To the OP, you may struggle at 18 to get a chalet hosting job. Most companies do look for people to be 20/21 or older for chalet jobs as they're looking for people to be a little more responsible. (Though legally they can't discriminate purely on age, so if you put in a good application and interview well, you might have a shot)
But, if you're happy with hotel work, general waiting staff, kitchen staff etc, then you'll have no problem. If you apply early and are remotely presentable, intelligent and have an EU passport then you should walk into a job. Don't expect decent pay, or working conditions, but you'll get accomodation, food and a season pass, plus a little beer money.
I worked a kitchen job when I was 18 fresh from school. It was great, none of the responsibility of a chalet job and lots of time on the hill.
As Rosbif said above, check natives.co.uk for alot more European specific advice and information.