Ughhhhh! I can't get my new Trek Incite 8i to work with my Trek 7100!?

Help! I've been trying to get my new Trek Incite 8i to work with my trek 7100 bike, for which I haven't yet found an intelligable answer. The stupid manual only has pictures; I found it extremely difficult to even put the CPU unit on the handlebar! I can't seem to figure out what to do! And do I install it on the front wheel or the rear? It would seem to me like the front wheel, being just along for the ride, would spin slower than the rear. But does it matter which wheel I put it on? And then there's the matter of proper placement on the spokes of the wheel. Where do I put it on whichever wheel? I've tried doing it exactly as the illustrations showed it, but when I took the bike out and rode it, nothing worked like it should. Remember that the 8i is wireless, so it can't be the wires, since there are none. Also does it matter which side of the wheel I put it on (is there a specific direction the magnet is detected)? Please help!