Elements is a very good program and has all the features I ever needed from CS2...I don't know what I'm missing with CS3 so it doesn't hurt me.
My advice: go for the cheapest editing software you can get (i.e. free). You can probably scrounge up old photoshop or paint shop copies for dirt cheap.
You don't need fancy editing software unless you are trying to get really artsy (which is fun, admittedly), or you are constantly having to bail out pictures with exposure problems, poor focus, whatever. If he knows how to use his camera correctly he won't need $600 of editing software when he is just starting out.
When I was a young(er) lad (about 5 years ago), my dad loaned me the ol' Canon AE-II, gave me a few rolls of Fujifilm, and I went out and learned to take pictures the good old fashioned way. With a lot of trial and error, or course. I guess what I'm saying is, especially with digital, you should be getting really good images out of the camera already.