One of the things that can sometimes help genealogists is to know the popularity of names at different periods and in different places. Names can very often date people, sometimes quite precisely.
One of the most spectacular examples in recent times is Nevaeh ("heaven" backwards), which in England and Wales at least has grown spectacularly in popularity for girls, thought not at all among boys.
You can find this, and other information on the popularity of names in England and Wales here Babies called Nevaeh in England & Wales since 1996.
One of the things I find slightly odd about these sites is that they are almost always called "Baby names", but those before 2000 are now teenager names, not baby names.
Another thing to watch out for is the way names change sex. That does not seem to have happened to Nevaeh yet, at least not in the UK, where it seems to be strictly a girl's name.
But when I was growing up, for example, anyone called "eslie was invariably male, and the feminine form of the name was Lesley. More recently, however, I've come across some female Leslies, and some male Lesleys. With some names, like Ashley/Ashleigh, it's impossible to tell.
That's OK when you know the people concerned, but when you are entering the names of relatives you've just discovered into a genealogy program it often wants to know their sex, and sometimes you just don't know.