I know a lot of new writers trip up on the difference between Authorial voice and Character Voice. Sometimes, they think they are the same thing, but nothing could be closer to the truth. This webinar concentrates on character voice, but it does lead in with an explanation as to both different kinds of "voices."
To wrap it in a nutshell: Your characters should all sound different. They should all have their own voice. When a certain character has the POV in a scene (and you must present every different scene in your book from a particular character's POV), everything the reader discovers, whether it's through setting, exposition, or dialogue, is filtered through that characters mind with his or her judgment acting upon it before the reader ever gets the information.
Certain characters will notice at different things around them. Someone who's lived their life in San Francisco, probably won't even notice the Golden Gate bridge as it comes into view while he's driving--he's seen it way too much. But if someone flies in to meet him and this person has never been to San Francisco, he's likely oohing and awing all over the place when he sees the bridge for the first time. Each character will phrase their words a slightly different way from the rest. Maybe it's a little stammer they have, or something about their ages (children see the world much differently than grown ups), but something is different for that character from all the others. This is where all your characterization, emotional growth, and story arc starts.
I will have a webinar about building scenes coming up, but one thing you want to do (unless your book is told entirely from one character's viewpoint) is decide ahead of time which character will have the POV in that scene. Do not change POVs within a scene. Only after section or chapter breaks should you change POV. Now a lot of people will point out very successful novels where this doesn't happen and my response to that is, "Fine, but this isn't their first novel published, generally, or if it is, you don't know how many others the author wrote before getting one published." What I'm trying to say is, yes, there is an exception to every rule and you can break the rules only if you know the rules and have a good reason for not following them. "To be different," is not good enough. There is a reason this rule is in place and that's so we, as readers, see your POV character as she sees the world. By doing so, we learn her insecurities, her strengths, her charisma (or lack thereof), and their motivations. Going this deeply into a character's POV allows us to empathize with the character and grow attached to her. Remember, your main character should become a surrogate for your reader. When she weeps, you want the reader there with you, right alongside her.
If you aren't writing a book from a single POV, then you have to ask yourself which character should be the POV character in a certain scene? Usually (but not always), you want to view the scene from whatever character has the most emotion at stake in the scene. This means, if you have a husband and a wife fighting in the kitchen, you might want to choose whichever one will have the most to lose if they split up. Or, you might not want either one of them. A better idea, might be placing the POV from their daughter who's down the hall with her door closed, sitting on her bed, and trying desperately to plug her ears.
That's it for now. Next time we'll discuss the difference between third person and first person and how that affects the words you use for exposition and setting. If I have time, I will dip my toe into the waters of Deep Point of view (also called "close" point of view), but my gut feeling is that will probably come in a webinar all its own later on.
Thanks for watching!