Not a very original title for a post about naming your characters. Plus, I've done posts where I've interviewed a number of YA authors (some VERY well known) about how they go about naming their characters. Some have complex rules about syllables in the first name than last, some mix and match sounds, some do research for cosmic significance, some go through the family tree, etc.
I'm too lazy. Plus, (shhh! a secret here-) not everyone in the family deserves to be in one of my novels or the character with their name would tick them off because no one wants to be the bad guy/gal. Avoid using family names, it can only lead to trouble.
So I cheat. Rather, I like to call it Inspirational Smack. When I need a name for a main character, I watch a movie or TV show.
No, I don't steal famous names. I steal names from the credits. Really. Sometimes a name just jumps out at you and smacks me in virtual face, it's so perfect. I read the names that scroll after a show ends, and get an endless source of unusual, typical, ethnic, and cross cultural names. Watch the wide screen and let Hollywood do the work for you. It's like walking through Macy's and seeing the most perfect pair of shoes; out of all the others, one pair seems to shine, drawing your eye and you know it's the perfect choice. Plus, these are real people getting credit for working so you have a valid case when someone says "No one would name their child that!" Yes they do, and it's in black and white, out in cyberspace.
And your character has been given an imaginary birth certificate with a legal name.
But don't stop there. Even if you have all your characters' names, you'll be writing more novels or stories, right? Start a list of names that just grab you. That's how I got the name for my main character in my sci fi, Lethal Dose. His name is Dalen. I saw the name in a book of baby names and knew that one day I'd need it for one of my works. It was on my list for several years and now has a body.
That's another great source: a baby name book. (I'm sure most of you know this.) I flip through the pages and when I see a moniker I like (other than the common ones like Sarah or Michael or Chris which I can just pull out of my head because we're surrounded by people with those names) I put it on the list. Then it's just a matter of picking a last name that fits. Sometimes zipping through the phone book can help, although I don't particularly like that method- it's too time consuming. You have to go through all the A's, B's, etc.
So, take the easy way out. Watch TV or a movie and solve one of the biggest problems of being an author: finding the perfect name for your character.