The best book I've found on POV in nonfiction is Vivian Gornick's The Situation and the Story: The art of personal narrative.
A few personal notes on POV...
First person: "I handed the vaccination records to the veterinarian. I wondered if the dog would survive."
(First person is limited by what the "I" in the piece can see, feel, hear and do. Easy to use and powerful.)
Second person: "You hand the vaccination records to the veterinarian. You wonder if the dog will survive."
Third person: "Tony handed the vaccination records to the veterinarian. He wondered if the dog would survive."
(Third person is -- to paraphrase Walter Mosely in This Year You Write Your Novel -- like a little person sitting on the shoulder of each character observing and reporting. Powerful, but be careful about where the little person goes. If the little person jumps too often, or too quickly, you may confuse the reader.)
Third person omniscient: "Tony handed the dog's records to the veterenarian. The universe unwound. The Andromeda galaxy moved a million miles in the time it took to pass the records from one hand to the other. The veterenarian thought, "I wonder if these records will help..."
(Third person omniscient is the 'voice of God' jumping anywhere in the Universe at will, looking at anything at any level. Very difficult to do well. Easy to lose the reader.)
Once you choose a POV, stay with that POV throughout the book.
Beware changing POV in mid-stream.