I think the iPod MP3 Players are the best and easiest to use. Depends on what you want. If you want the capacity, obviously think about getting the iPod Classic.
However, if you want something that is certainly a lot more fun to use, go for the iPod Touch. How big is your MP3 collection? Have a think about that before buying one. I guess it is easy enough to remove songs and replace with others though, just taking the songs you need.
If you were going to buy the highest capacity iPod Touch for example, I'd be thinking about buying the iPhone 3G instead because the iPhone is basically that with a phone, bluetooth, GPS and obviously a lot better if your on the move a lot, using applications that require some form of internet connection so in those situations, it would be better to have the iPhone.
Not sure the best place to buy one. Maybe Amazon or just go to the Apple Store Online.
You won't get a student discount from Apple, well not to my knowledge. I asked about this as I am a student myself and they told me that the discounts are only available on the MacBooks and other educational products that they sell.
You can buy songs from iTunes but you can download them from elsewhere and import them into iTunes, same with CD's. It's very easy to do.
If your sure it's just an MP3 Player that you want, then go for either the iPod Touch or iPod Classic. I think the touchscreens are much more fun to use. There are so many Apps you can buy or get free from the App Store.
I really like the Facebook Application for example and only being able to use it where there is wi-fi would annoy me as I want to be able to access it wherever there is wi-fi and O2 coverage. Some Apps don't work on the Touch as it lacks some of the hardware in the iPhone. One of those applications would be Shazam as the Touch does not feature a mic.
Loads of games for the iPod Touch/iPhone. Look on the App Store or go to YouTube and see for yourself. It's a good idea to check there before buying as well.
I did all of that, thought about getting the iPod Classic, iPod Touch and then thought well if I am prepared to spend that sort of money, I will go for iPhone 3G 16GB.
Apps do take up a fair bit of space, if you have a lot of them. I've almost filled half the capacity of it with all the music, video, photo's and apps I've got.