Point of View came up a lot in the MLS contest. Some people like first person, some like third person, some like omniscient, some don't seem to know what they like. They just want to read and would you please stop talking about writing?
Point of View can be described as the camera through which the book is filmed. The camera angle determines what gets shown and how. The Blair Witch Project, anyone? Or Sixth Sense, for that matter. The entire movie is filmed from Bruce Willis' perspective. We only know what he knows, and eventually we are just as surprised as he is (I was, anyway).
In Star of Justice, the camera falls out of the sky to land on Caissa's shoulder as she signs her name to the letter she is writing. I say shoulder because the book is written in third person. If it were written in first person, the camera would be inside her body. Maybe more on that in another post.
From the moment Caissa is identified as the viewpoint character, anything you read should (I hope) be firmly within Caissa's viewpoint. You will experience and know nothing that she doesn't experience and know.
This understanding of viewpoint is important for one reason with two sides.
It focuses your writing on one person's understanding of events. The reader can agree or disagree with that one person, but she has a frame of reference for viewing the whole story.
And, it limits the information the reader will get.
This is important.
Choose your viewpoint character based on the information you want your audience to have. Some characters know too much. Take Sherlock Holmes. Can you imagine a story written from his perspective? He's got the whole thing figured out the moment the inspector walks through the door. How much fun would that book be to read?
Some characters tell a better story, even though they aren't right in the middle of the action. This would be Watson. He's a nice, normal guy who doesn't know the origins of talcum powder.
Consider which of your characters will tell the better story and use that character to do it.
This doesn't mean you have to limit yourself to only one viewpoint per book. You may use as many as you wish, as long as you understand that every viewpoint change will take a toll on the reader.
For an author, how to tell the story should be considered as carefully as what story you're going to tell.
And I've never seen The Blair Witch Project. My motion sickness couldn't handle the shaking vid-cam.