Okay currently there are 3 types of iPods on the market. They are known as: Video (aka iPod, iPod Video, 5G), Nano 2G, and the Shuffle 2G. A number followed by G stands for the generation. So 2G is Second Generation. There are also special U2 versions (as in the rock band) of both the Video and the Nano that come in Red, which I'll get at.
You will want to know two things: his color preference and size of music collection.
My personal feeling is this. When a teenager asks for an iPod or an MP3 player they generally want a Nano, and you want to target the 4GB if you feel the price is right. It's light, very portable, the new 2G is very durable (can be thrown in a backpack - the case is aluminum), and it's what their friends have, want, or talk about.
I have a black iPod Video 60GB model (see below), and I use it every day as I walk or work and even in the car.
DW has a Black 8GB iPod Nano (but it's in a green case), and she uses it as a pedometer because she has the Nike attachment for it. The pedometer can only be used with a Nano, which is why she has a Nano and not a Video.
You will want to familiarize yourself with this page (and I'll help you below):
http://store.apple.com/1-800-MY-APPLE/WebObjects/AppleStore?family=iPod
The Video comes in two flavors and two colors: 30GB (GB just like the size of a hard drive - because it is a hard drive), and 80GB. There was a 60GB version that the 80GB recently replaced, but it's been discontinued though you may still find some on the shelves. The two colors are Black and White (note back is metallic in both cases, front is the color). They are prone to scratches.
The 80GB will cost $349. It holds up to 20,000 songs, and plays video.
The 30GB will cost $249. It holds up to 7,500 songs, and plays video.
The U2 (30GB) will cost $279, and is identical to the regular 30GB, but it's black with a red control dial, is engraved with the signatures of the members of U2, and comes with some special U2 videos only available on the device and nowhere else.
The Nano comes in 3 flavors and 6 colors: 2GB (silver), 4GB (silver, green, blue, pink, red), 8GB (black, red). They have an aluminum case and are more scratch resistant than the Video as a result.
The 2GB will cost $149. It holds 500 songs.
The 4GB will cost $199. It holds 1000 songs.
The 8GB will cost $249. It holds 2000 songs.
Now at this point you will have noticed that the 8GB Nano is the same price as the 30GB Video, and you're probably saying why get the 8GB Nano at all ever. Well there are a few reasons:
1) Notice the comment of DW's pedometer above. The Video can not use the Pedometer. Since DW's primary use of the Nano was for walking this was a crucial feature for her so she got a Nano over a Video.
2) Weight, the Video ways about 10 times what a Nano weighs.
3) Size, the Nano is about 25% of the size of the Video.
4) Color choices.
5) Durability and Resiliance (it is Flash Memory not a hard drive, and is made with an Aluminum case). Read as: Nanos are better for kids.
Finally there is the new 2G Shuffle. This comes in one color: silver. It is 1GB and can therefore store about 250 songs. It also does not have a screen which makes it a little bit different in terms of control (see below). However it weighs only a few ounces, is the size of a matchbook, and has a built in clip (could be worn as a broach).
The Video and the Nano have an LCD screen, you can surf your music and choose what you play, where you start, etc. The shuffle lacks this. You can only listen wherever it picks up (depending on settings you can only make inside iTunes - the Nano and Video as I said can do this on their own), and you can only jump to the next or the previous song, you can't pick a start point.
The Shuffle is $79.
Now why should you know the size of his music library? So you know what size works for him AND allows him to grow his library.
For example if he has 10 CDs. That's about 100 songs. A Shuffle works and he has room to grow.
However if he has 50 CDs that's about 500 songs. That will fill a 2G Nano, so a 4G Nano would be the best choice as he'd be able to carry his entire library and grow.
A few things you should know up front...
Things like cases, and lanyards cost extra, but not much extra if you spend time to locate them. I shopped and got Cheryl's green case with lanyard for her Nano for $12. Video cases are a bit more money. There are shuffle cases, but I can't see getting them, since it already has a clip and at <$100 it's a throw away item. If it breaks, get a new one.
You are married to iTunes. Other things will work, but you'll still need iTunes to upgrade your iPod (Apple updates about twice a year). iTunes is both simple and complex. Your son will probably want to get songs from iTS (iTunes Store). However, you should monitor him closely with this, as I've heard horror stories. I suggest that instead of backing his account with a credit card, you buy iTunes Store gift cards that you can find in just about any chain store (
Best Buy, Target, Wal-Mart), and have him use these. This way you can both monitor and limit his purchases.
If you have more questions don't hesitate to ask.