http://www.programmingart.com/products/key/keymanual/images/handsForManual.gif http://www.simplybodylanguage.com/images/finger-names.jpg

Thumb, forefinger/pointer finger, middle finger, ring finger, pinkie/pinky finger (or just "pinkie/pinky").

Thumb, forefinger, middle finger, ring finger, pinkie finger.

The forefinger is also called "the index finger", and the pinky is sometimes called "the little finger". I'm not sure if there is a preference for certain terms in the US, but I'd follow Sarah's suggestion. In some cases you could simply call them "first finger / second finger / third finger / fourth finger".