How do i approach her....again ?

theres this girl that iam completley infatuated by, i approached her a couple weeks ago and got to know a little bit about her, we chatted bout school and things like that, so she asked for my email address cuz she said she might need help wit a particular ignment, its been a week and no email, i see her tommorow and i was wondering if i should approach her again and if so whats the first thing i should say, or should i parlay for a bit and stay out of her way, i also want her number but i dont kno how to ask for that either...thanks