It is a 16 years old boy, almost 17.
And, all the more reason not to get a Ribbon or Tube or other mic that doesn't do well when used as a lawn dart. Not that they'll be used as lawn darts, but it very well could be I'm in a hurry, toss it on the bed and run. Oops, I MISSED.
Shure SM57 or SM58 ($50-ish USED / $100-ish NEW)
plus an interface.
I got an M-Audio Mobile Pre ($80 on craigslist and quite common).
I actually had two at one time so I could use a phantom powered and non-phantom powered mic at the same time. Lots of input and output options, but limited in the 16/48 sample rate and only 2 channels. Not that you need more than that for most things voice over. Unless you need the really good stuff for the super low noise floor and other perks only available on the good stuff.
There's many NEW-ish ones that do 24/96 over USB. USB mics combine the mic, interface and preamps all into one package. But you get a number of limits going that route, and not always the highest quality of gear. Plus they have virtually no resale value. Snowball is the normal option there. Some of the MXL (cheap made in china) mics have USB options as well.
Edirol UA-25 or something like that seems to be the interface of choice these days in terms of USB interfaces. EMU 0404, and others. It really depends on what the goal is with this endeavor? Just to skype with mom over the internet? Or something more commercial?
Basically plan on:
$100 mic
$100 interface
$50 cable + stand + pop filter
(maybe more depending on gadget count)
(maybe less an SM58 has it's own pop filter of sorts)
You can buy used and cut most of that in half. With the possibility of resale-ing the gear at costs.
You can buy a combo USB mic and lower the price by about a 1/3rd. But you'll almost have to give it away to get rid of it.
Or you can forgo most of this by using the mic on your laptop / webcam / camcorder / telephone / CB / ......... But not really much hope of achieving pro-ish results that way. And probably something to do with a soldering iron and a grain of knowledge as well.