A character's last name has many associations such as suggesting ethnic background. Wozniak does not have the same overtones as O'Reilly, Johnson, Goldfarb or Garcia. The moment you choose the last name, you bring the character ethnic and racial baggage.
The name of a character is also the label readers use to keep them straight. Give characters memorable, different names.
Try to make sure your major characters' names start with a different letter. Don’t have a Myron and a Milton as major characters. Try to vary the lengths and the sound patterns. It's hard for readers to remember who is who if all the names follow the same pattern. Mono-syllables like Bob, Bill, Tom, Jeff, and Pete are confusing.
Just as bad is the other side of the spectrum; names which are too flamboyant and bizarre. Available Jones belongs in a comic book, not in a novel. A bizarre name will draw attention to a character and unless that's what you want, don't use a bizarre name.
Collect names from Google news or magazines.
Find lists of names of people who participate in a race, support a candidate or audition to play Iron Man and steal the names and enter them into your file. Other sources for names are sports rosters, television and film credits, and obituaries. Foreign films and magazines can help you, as can high school and college yearbooks.
In an online class, a student asked me this question: "I'm tempted to refer to my protagonist by his first name. How do I refer to the other characters? Do I base it on how the protagonist feels about the character or what his relationship is with the character?"
In my Veronica Slate books, I referred to her as Veronica but others, depending on their relationship, called her Vee or Ronnie in dialogue. Protagonists should have relatively plain names, easy to remember, and to give readers a clue to their characters, like Veronica Slate, Edward Cullen or Peggy Carter. A character's name is the first clue your readers have about the character and you don’t want to make them too difficult to remember.
As far as other characters are concerned, you should govern the name choices by how near or far you want readers to be. If you want readers to have sympathy for Sarah Sylvester, call her Sarah. If you want readers to dislike Victor Jeffries, call him Jeffries.
Try using a first name for someone you want readers to have sympathy for, like your protagonist. Use the last name for anyone you want readers to be distanced from or someone you want to seem aloof to readers.
Some other pointers about character names:
• Obviously, avoid names, which are well known, like Hilary Clinton or Tina Fey.
• Stay away from names that give most people an immediate bad impression, such as Adolph.
• Be aware of who the character will interact with. If Ali Court will be in scenes with Al Courtlas, you should change one of the names.
• Avoid having two names that are too similar in the same book, such as Jane and Joan or Bill and Will. Readers will be confused.
• Character names should be gender-specific. Use Christopher and Patty instead of Chris and Pat.
• It’s best not to name two characters with rhyming names, like Gary, Barry or too similar in sound, like Maggie and Reggie.
• Characters should be called by one name consistently. If he's Joe Adams, you shouldn’t call him Joe, and later on call him Adams. Robert should not be Robby or Bob in the same book.
• Use age-appropriate names for the era in which the character was born. Lillian and George are older than Jim and Vicky, who are older than Jason and Tiffany.
One hint, from someone whose protagonist was named Veronica Slate. I had to type “Veronica” about three hundred times in each book. By the time I got to the third book about Veronica, I wished I had called her Lyn.
----- (From NOVEL SECRETS available in paperback and Kindle form.) http://www.amazon.com/dp/B0189VGK32