Ill try a quick one....first, at the top of the mixer, set up your effect in the window.....get the parameters set the way you want.....
then, slide the slider (in between the master channels effect window and the auxillary effect windows) between 1 and 10...I usually push it pretty high up.....
then, if the effect is set up on aux 1, then you have to go to the aux1 fader/slider for each track that you want to pass through that auxillary and use the slider to show how much of the track you want effected....all the way up is 100%....also, you have a fader so that you can pan the effect....for instance you can have a guitar track thats panned left, butpan the reverb to the right (can you say Eddie Van Halen).....
this is a very bad explaination,but i hope it can help....if you still cant get it, email me a phone number and ill try and talk you through it....