Good earphones that fit as the earbuds don't fit this age (my daughter is 8 and has one). I'd suggest a dock for charging and listening to music if he does that. I like that the dock makes the ipod have a "home" and it's less likely to be misplaced.
Otterbox makes great iphone cases so look there and then buy on Amazon cheaper (or ebay).
Itunes cards are a must. If this is for Christmas you have some time to download a free video converter and download some of your own movies onto the ipod. I use Handbrake but there are many others out there.
I also downloaded a bunch of educational games. This way it wasn't all "games" if that makes sense. My friend is a teacher so she asked on twitter for me and gave me a big list (which I don't have so I'm sorry about that).
Oh - I was just told that the iphone and ipod have scratch proof glass now for their screens. I haven't researched that yet but look and see what you find before buying the protective film. If you do end up getting a film the zagg ones are pricey but really worth it.
An Otterbox defender case, an extension cable that will work for data, a clock radio that charges the ipod, and iTunes cards.
The Otterbox case is a PITA to remove and it won't sit in a dock with the case on, but Amazon has $9 extension cables that will work with any dock and case. The Otterbox case provides very good protection for the ipod (and has a built in screen protector so you don't need a seperate one).