you gotta play stuff that will capture the audience, so dont go playing progressive stuff
try playing some uplifting stuff, i mean really uplifting like...

cosmicman - i love you (1.4v)
orion - rush (angelic mix)
westbam vs red jerry - wizards of the sonic (matt darey remix)

play stuff like that, that is uplifting, and mix it together, dont make the songs longer than 3 minutes or else people in the class might get bored or something

I just thought of 1 u could play that is just trance at its best


PPK - Hey DJ 2001 (Trance Mix)

I have no idea where I got it from, but it's got a wicked intro and sounds like a dream

Hey, cool project for school. I wish I could have done something like that.

For samples I would play:

a few commercial tunes maybe
darude - sandstorm
dj sankin and friends - protect your mind

then some good tracks (these are some that got my friends into trance):
exor - the bells
samui - the big blue


Then play Bangin choons like:
iio - rapture (deep dish mix)
DJ Tiesto - Urban Train
and anything else that is smokin