If you don't know what it is and how it could change your life,
to be a Computer Science student?
What careers are possible?
Who is good at it?
CS Careers and Degrees - from the ACM
Common Misconceptions (e.g., Girls won't like it - nonsense)
MIT's 4-Week Summer Program for High School Girls (there are more such programs for boys and girls; just search the net)
More info... (Uni. of Colorado)
More info... (Uni. of Washington)
ACM's "A Model Curriculum for K-12 Computer Science" report (see yellow highlights for main ideas)