It comes with pretty much all you’ll need, aside from the games. Battery? Check. Docking station? I don’t know that there is one available yet. There is a power cord included for charging though. And it comes with a 32MB memory stick, which is more than enough unless he’s planning on using it to store a lot of picture and video data. It’s plenty for its main intended purpose: gave saves.
What kind of games does he like? The one that’s definitely a must buy is Lumines. It’s a puzzle/music game akin to Tetris, and oh so addictive. In the same vein, Mercury is also pretty cool in its own way, though it gets hard as hell in the later levels.
If he likes a good racing game I hear Wipeout Pure is excellent. Metal Gead Acid is a cool card-based strategy game. Tony Hawk Underground 2 translated pretty well to the system too.
One game I’ll go ahead and not recommend is Smartbomb. A promising premise, but it’s a shoddily made game if I’ve ever seen one. You’re supposed to be making split second decisions and moves to defuse a ticking time bomb, and the controls are horribly unresponsive! It’s easily the most frustrating and most unplayable game on the system.
Hope he enjoys the system! I haven’t touched mine in a while (nothing has come out lately), but I’ve had lots of fun with it, and I’m looking forward to what’s coming out through the end of the year (Namco Museum, GTA, etc).