Heyyo,
003, that's reccomended, BUT look at their budget. Remember, not everyone's got big money to spend on comps. He probably just wants a decent gaming rig. One that'll keep the framerate smooth, with decent looking graphics.
Quick list...
cpu AMD AthalonXP 3000+ $115.00
http://www.newegg.com/Product/Product.asp?Item=N82E16819103381
mobo: gigabyte GA-7N400S-L $58.00 (now gigabyte ain't the best, but they do have nice prices on their mobos)
http://www.newegg.com/Product/Product.asp?Item=N82E16813128275
vidcard: EVGA 6600GT ($144.00 with mail in rebate! nice)
http://www.newegg.com/Product/Product.asp?Item=N82E16814130220
Now it comes with onboard sound, this should be ok for a budget comp, otherwise you could always get like an audigy gamer or something.
RAM: Samsung 512MB PC3200 DDR Ram $58.00
http://www.newegg.com/Product/Product.asp?Item=N82E16820147111
Now I say Samsung's great cause I have 2 sticks of this ram and it works fine. Cheap ram, good preformance. Samsun rocks with monitors and ram man.. just sweetness.
Now this is $375.00 without S&H and Taxes. Plus, if you needed stuff like HD's, a case n' such I left you some funds there to help settle that gap. If you wanted you could see if you could find a more higher-quality mobo, might cost you an extra ~$15, but I'm too lazy to dig one up, lol. Asus is definately one of the highest quality mobo makers out there, so they're always good to get.