Don't forget about PRAYER, ladies!
While it seems like prayer isn't very "active," and people will apologize for it (I'm sorry, all I can do is pray for you), I think prayer may be our most powerful spiritual weapon.
I would begin praying for your classmates. If you are involved in a youth group or other gathering of Christians, ask them to pray for your classmates as well. The more committed you are to prayer for these people, the more compassion and love will grow in your heart for them.
Also, prayer helps prepare YOU for those moments of opportunity to verbally share God with others--it will help you recognize those moments, and give you courage to speak.