Another frequent question I get is how do I name my characters. Let's start with some of "the rules."
Rule 1 - don't name two characters with the same name, or the same first initial. This avoids confusion. Also, don't name characters with "rhyming" names, like Eddie and Betty, or Terry and Mary. I did read a book once that had two characters with the same first name. One of them was killed off about halfway through, so I was thoroughly confused when the second one showed up without warning.
Rule 2 - be conscious of the visual a certain name provides. If you name a character John Wayne, your readers won't see a businessman in a suit. Iconic names will immediately bring something to mind. Make sure your character's name matches the image you want to project. "Susie" isn't likely to be mean and nasty, whereas "Susan" might want to be treated with respect. "Sue" might be an easy-going person.
Rule 3 - avoid giving a character two first names (another rule I flubbed starting out). John Thomas. Christian Scott. People will confuse which name is the first one and which is the last.
So where do I get my character names? Well, let's face it. the ones that come immediately to mind are used quickly, and I have to keep a character map to keep from reusing them (and I will admit I failed in a couple of places when I was first starting out). Two of my favorite "man" names are Tom and Bill (no, I don't know why), and those two names continue to creep in on me. I now have a database of names that I have used and which books I used them in. This helps for continuity in a series, and it helps from using repetitive names or alliterate names (with the same first letter). So now that I've used Tom and Bill, where do I go to find another name?
There are baby books, and when I've been searching for something ethnic, I go that route first: "What is an Irish boy name?" Some people use names of the teachers they had in grade school, or people they've met briefly. One of my writing buddies had someone she worked with ask to be put into one of her novels. (I have friends like that, too!) It's a name, it doesn't have to be who that person is. I've used disc jokey names. I've opened a phone book. I've gone walking in a cemetery. I've even taken last names from street signs. And my most recent favorite place to get names? Professional sports. I've combed through the World Cup soccer teams, I've stolen a couple from the NFL. I've borrowed some from baseball and some from basketball. Generally, I cross-match first and last names to prevent association with the real-life counterparts (who are donating nothing more than their names). And then there are the ever-popular middle names. My grandmother's middle name, etc.
Usually, I pick out my characters' names first, and the story tends to revolve around them. The names speak to me as loudly as my concept does, and there have been times I've had to change the names. The story I'm working on now started out with Elisa and Tom (! - go figure, Tom? Maybe that's like "every Tom, Dick and Harry?") I've already overused Tom, so I had to change out my main character's name. I think the new name works! And Elisa is parallel to Marissa (from the first in the series, a character who figures prominently in the second in the series), so her name had to change, too. I think my characters are happy with their new names, and along with recording the names I've used, I'm now recording new names to use as they come to me to make my life easier as I work on new stories!