Read, read, read!! Read what interests you.
Take Algebra and Geometry, if possible.
Work hard and get good grades.
Get involved in school-sponsored activities such as sports, music, yearbook, art, speech/debate.
Volunteer for community service: at the library, at the museum, at the assisted living facility. Get involved and help people.
Talk to your parents about saving money for college.
Save as much as YOU can.
Register for Honors/AP as early as your freshman year.