First off, what is it? Well, honestly, this may sound like a stupid question to some, but I believe there's no such thing as a stupid question. (Um, for the most part.)
Some of us do NOT know what POV is or why it matters. When I wrote my first novel -- a 400+ page tome of historical romance, anguish and head-hopping melodrama (cringe) -- I knew nothing about Point of View. And you could tell by reading that story. Hey, it would've made a great travelogue! ;)
POV, as we call it, is the viewpoint from which a story is told. There is first person: "I", "me", "my", etc...which is popular in most of the chick-lit genre; third person: the one I prefer to read and write; and omniscient ... in other words, the all-seeing narrator or 'God', if you will.
Some writers and editors are POV purists. They insist on one POV per scene OR chapter. Using more than one POV in this way is commonly known as 'head-hopping'. To be honest, you'll find more head-hopping than not in most widely published novels today. Particularly in the romance genre. Especially by those with the Big Names.
The Evils of Head-hopping
or... "If so-and-so can get away with it, why the hell can't I??"
The reason you might not be able to head-hop your way through your first novel is, again, simple:
1. Because 'so-and-so' has been around (as in multi-pubbed) for a while...
2. Does it well so no one cares...
3. Is a good enough writer in general that many sins can be forgiven...
4. All of the above.
If you insist on writing it your way -- I say, "Go for it!" But for all our sakes, do it right! The biggest arguments I've heard for avoiding the ping-pong match of flitting from one character's head to another are as follows:
*The reader loses track of who is thinking, feeling, or saying 'whatever' from one paragraph or page to the next. Nothing is more annoying than having to retrace your steps, go back in a book and figure who the heck is talking! It's not only a nuisance, but it pulls your reader right out of the story.
**It's sometimes difficult to 'identify' with a character if you don't spend enough time in their thoughts...feeling and sharing their emotions. If you only get snippets of the heroine's feelings before you jump into the hero's, your reader may have a hard time connecting and/or caring. If they don't connect/care, then they may lost interest in the story. NOT good.
***Sometimes, you can get a stiff neck (mentally) trying to keep up with all the ping-ponging. Sounds silly, but it's true. Nothing gives me a worse headache than trying to keep track of who's saying what to whom over the course of a 200-300+ page novel.
Okay, so what to do?
First, you need to decide what type of POV works best for what you're writing. Then decide up-front how you're going to handle the POV switch -- if you have one. Obviously, in a first-person narrative, you won't have that problem.
Believe me, I can tell you from experience that it's a lot easier to make that decision from page one then to have to go back and edit the entire book. I've done it and it stinks. I have one terrific writer friend who tried to 'fix' his first novel -- a head-hopper -- and gave up. He's in the process of re-writing it completely.
Basic *Rules* of POV:
1. Only 'show' or 'tell' things that the POV character can actually experience/see/feel/know. Don't have your heroine stare at herself in the mirror so she can think about her beauty -- or lack there0f. She'll lose a lot of sympathy right there. Don't make your hero a mind-reader who can decipher every thought or emotion on the heroine's face ... well, unless it's a paranormal story and he can really read minds. ;)
2. Avoid omniscient POV at all costs. It gets old, folks, and most of us don't like it much.
3. Again, decide how to break up the POV if you're going with third-person. I like to use scene changes and chapter breaks. But make up your mind and try to stick with the plan. Revision is available, but it isn't always a picnic.
4. In the end, thumb your nose at the *RULES* and head-hop away! Just do it well.