Names define characters. Personal experience, phrasing, culture, and history all influence how the audience will perceive a name. Choosing the proper name to fit a character and their story is more important than a simple identifier.
Feel free to jump ahead to the data if all of this is old hat to you.
Names tell the audience about the character. Azog the Defiler or Captain Picard include titles that speak to their positions in their universes. A basic trait is granted without any other context (cruel and authoritative, respectively).
Complicated, unusual, and repetitive names without a purpose detract from content. The unfamiliar requires more brainpower on behalf of the reader that would otherwise be spent on the story. Emmalynn or Maddisyn distract while Emma and Madison do not. Avoiding similar names makes differentiating the characters a far simpler task. Mya, Mary, and May run together where Alice, Cathy, and Zoey do not.
The audience's personal like or dislike of a name can be hard to measure. A bully from the neighborhood or an old crush from grade school place meaning on names to specific people that might be difficult for the author to guess. Less common names from larger popular culture can safely be associated with their owners. Naming a character Barack calls to mind the US President.
Literature for Modern United States
Stories set in the recent century of the United States can benefit from codex10's name tool. The charts show birth rates, population fraction, and common ages for the name during each year.
This tool helps identify popular names on both time and geography. For example, Maggie was a prevalent name in the 1920s South, but little elsewhere. By this data, overwhelmingly 70-80 year old Maggies are from the South. Maggie has gained some popularity in recent decades and newborn to 20 year olds now live in all regions.
Age Targets for Children
Stories intended for children are especially sensitive, since younger readers are often quite choosy about the subjects of their stories. As a rule of thumb, adolescents want their heroes to be a few years older than them. Giving those characters appropriate names can be tricky, as trends alter vary fast and people intuitively know which names are older or younger. Target 8-9 year olds with a 11-12 year old character.
The name tool makes vetting specific names easier. Choose a name (and region, if you story is specific to a part of the United States) and note for the orange dots. The clumped dots show the most common age for the name during each year. If working in current era, check for clusters of dots on the right of the graph.
For example, take Nathan in the United States. Elder Nathans of ~30 are prevalent, but the younger Nathans cluster around 9-10 years old. Drilling into the different regions, Nathan in the Midwest has far fewer juvenile Nathans and most are over 30 while Nathan in the West is much more likely to be even younger at ~6 with a few Nathans in their 30s.
Look up a Name
Give codex10's name tool a try! Even if you don't need the research, looking up peoples' names is fun!