The positive to the positive point under the bonnet (with the red plastic cover) and because the standard C-tek leads aren't long enough to reach the negative 'bolt' on the suspension strut tower, I always just clipped it to the nearest suspension strut nut.
Some people 'hard wire' them by drilling a hole in the car's positive point and bolting a cable connector to it while anywhere with a good earth can be used for another cable connector.
As said above, the power lead will fit between the headlight and the bonnet. The charger itself can go anywhere it won't foul the bonnet shutting.