My middle finger for the wheel and right-click, and my index for left-click. My mouse exclusively gets my right hand, though, since I only type with my left. :o
Really?
That interesting.
I can't type without my right hand. I was taught how to type in Junior school, and I've learnt it to the extent that my right hand always controls the right of my keyboard.
I even keep my fingers in the "safety/default" position.
Fingers on left hand are arranged (From little finger to index) on A, S, D, F. Occasionally, I keep little finger on Left Shift for easy shifting.
Fingers on the right hand are arranged (Index to little finger) on J, K, L, ;.
Occasionally that twists though, depending on how I'm sat, so it's J, I, P, [. That way, my little finger is close to press backspace.