I have a H100 - they're fairly similar to the H80 - and apart from the standard TIM aplication/ heatsink fitting procedure, you can just do whatever is easiest or neatest. 
I have my fans pushing external air through the radiator into the case although many people choose to have them exhausting. My radiator is attatched to the top of my Phantom 410 case with the CPU heatsink oriented vertically with the hoses coming out of the right side. The choice is entirely up to you though - the differences in temperatures from radiator/fan positions would be negligible as far as I can see.
I'd choose closed loop systems like these over large air coolers any day - fit yours and see why!