I recently read a blog regarding the writing element of point of view (POV) in which the blogger stated that omniscient POV was lots of fun because you could be in everyone's head. When I began my book five years ago, I did what is referred to as head-hopping. This means that within the same paragraph I had more than one character's thoughts available to the reader. The main problem with this is that as a reader you want to know whose point of view you're in. Or at least I do. When my editor pointed this out I began to read extensively about POV's so I would not make this mistake again.
First lets go briefly over the different POV's a writer can employ:
I started the car and pressed down hard on the gas peddle but nothing happened."Hey!" I yelled to my brother, "what did you do to the car?"
I watched his ears turn pink, a sure sign he was lying.
Here we are in one person's head...she/he can only deduce what's going on with other characters by what she/he sees, hears, smells...etc...
1st person present:
I slip off my shoes and switch on the T.V. This day has made me cranky. I need a glass of wine. I pick up the bottle. Only a drop left. Damn! Why didn't I stop at the store!
This is a fun and immediate way to write but the narrative can go too quickly if you aren't careful.
He watched the line of orange disappear over the western mountains, leaving a sky the color of pewter. Soon it would be completely dark. Why had he decided to come down here alone? In the distance he saw a rider, a woman by the look of it. He cupped his hands around his mouth. "Haloo!"he called, listening to the echo bounce off the canyon walls.
A wave of her right hand told him she had heard. It was several minutes before she drew close enough to make her out. Her dark hair was tangled, matted with sticks and leaves.
"What are you doing here?" she asked in a thick accent.
His heart pounded. He knew her, why didn't she recognize him? "I...I..." he stammered, trying to collect himself.
Here we are also in one character's head. In the next chapter or even the next paragraph we could switch into her head but if we did it now it could become confusing and irritating. We want to connect with one person at a time. We want to identify with this person.
The three teenage boys looked up at the sky as they made their way down the hill. It was lucky for them there had been no rain, otherwise the track would have been too slick for their light canvas shoes. When all was said and done they enjoyed each other's company despite their very real differences. In the lead was Ed, sharp-faced and an even sharper tongue. Behind him was Jake, short and heavy, a grim expression on his thug-like features. And following several paces back was Mel, the one with the gun.
In omniscient we have a story-teller. One who knows everything but is unnamed. If these boys speak to one another we can know all their thoughts because the story-teller knows. But it's very difficult to write in this POV correctly. Tolkien is a master at this, and we all recognize the fairy-tale feeling of this POV. We could have a fox looking out from his burrow commenting on the goings on...or a tree with thoughts. In this POV we look at the characters from a distance.
here is a link to a very good article on this subject: https://warriorwriters.wordpress.com/2011/08/22/deadly-sin-of-writing-5-p-o-v-prostitution/
I have not attempted to write in omniscient POV because I prefer the intimacy of 1st or 3rd person. And also because I'm afraid I would screw it up. My trilogy is in 3rd person with several different POV's separated by chapters or paragraphs. The sequel to the trilogy I've begun is in 1st person but I'm finding it limiting in some respects.
The other important thing to remember is that if you decide to switch from 1st to 3rd or vice-versa, it is not an easy fix. You can't just change 'I' to 'he/she'. The Moonstone was originally in 1st person and I changed it to 3rd-- a LOT of work! And of course this is doubly difficult if you're employing omniscient. There are other POV's I haven't mentioned here because I don't know enough to write about them--I have written one story in 1st person present--tenses are a subject for another day!
I may have made mistakes here as I'm learning as I go. There are many articles on this subject and many with false information ...here's a link to another valuable article if you'd like to read further: http://www.the-writers-craft.com/omniscient-point-of-view.html