This one's the most detailed approach I've found so far.
Umm ... chosing a snippet from that site at random ...
Having established the foregoing difference in distinctiveness, the audibility of a narrative voice is best understood as being a matter of degrees. In fact, following Chatman (1978), narrative theorists often use the oppositional pair overtness and covertness to characterize a narrative voice, adding whichever qualification or gradation is needed
I don't have the brain cells to follow that right now. Maybe after another cup of coffee.
POV is
where the reader sits, when she drives through the story. It can be behind the character's eyes, looking out. Or it can be six inches under the ceiling, floating around like a ghost, using a wide angle lense to see everything.
POV is also
who the reader becomes, in her imagination. It is the thoughts and attitudes and knowledges she incorporates into herself as she rolls along.
Depending on what Person you're writing in, you have slightly different approaches.
With First Person, you insert yourself into the story.
With Third Person, you climb into the character's skull, close the door behind you, sit your butt down on the soft gray brain tissue and lean over to look out the eyes.
A writer's approach to POV begins with the writer's immersion in the character. Some exercises for doing this are --
here,
here,
here,
here
Find the exercises themselves by going to the left strip on the page and double clicking on 'Writers Exercises' and going back to the appropriate month. Seeing what other folk have done with those exercises and the discussion of them may also be helpful.