I was shown how to use touch typing by my mother, but taught myself a different system on the teletype machine at school used to interface with the computer (pics are at my post on this
thread.) The system I use involves the first two fingers of each hand for most keys and my thumbs for the space bar. The little fingers are used for the shift keys on either side. My technique is a bit like playing a piano in that there is no set key for a finger but it is instead based on the proximity of the fingers to the next keystroke needed.