Take a year off (and do something with this year) and then consider going to college.
Get a Microsoft certification
Volunteer for a local stage company
Volunteer to help at an inner-city school
Become a prison guard
Learn to create web sites and start a business helping small businesses increase their profitability
Fight forest fires during the summer
Volunteer for the kind of company that you eventually want to work at (i.e. offer to work for free at an advertising agency if this type of work has appeal to you).
Work at a ski resort
Create a blog on a subject that excites you and find a way to make it a profitable business.
Graphic Web Design