Watch the Left & Right Hand online guitar lesson by Richard Gilewitz from Guitar Foundations
Fortunately for musicians worldwide, there is a universal language allowing a consistent fingering and notation for both the left and right hands. Many classical guitarists obviously are familiar with the p, i, m, a naming convention and it is encouraging to see that many steel string fingerpickers are catching on as well.
The left hand for fretting is commonly agreed upon as 1, 2, 3 and 4 from index to pinky, respectively.
Not to leave out the left handed player, all can be considered reverse for the two hands if you might prefer to play that way.