Macbook Air or Macbook Pro?

I'm currently a highschool student that has about 3 more months till I graduate. Then around fall time I will be heading off to college. Right now I use my parents Mac from 2006 to do all my school work and it's horribly slow. So, I decided I'm in need of an upgrade to have for myself.

I'm definitely going to get an Apple product for college (No talking me outta that), but my question is: Should I get a Macbook Air or Macbook Pro? also .. What size screen should I get? (Not paying attention toward price, just on what the laptop can do and benefit me most from)

I don't know which one will benefit me more, nor what makes the Pro a "pro".. Heres some background on my daily usage:

  • constantly downloading music
  • surfing the web
  • on youtube
  • working on school projects
  • using iMove to edit some videos (not often but every once and a while)
  • importing photos from camera/iPhone to iPhoto
I'd really like everyones input on which laptop I should get!