Was really looking hard at an 06 but after doing some research on power delivered down range, I am leaning toward a .270.
My son is also just starting to hunt and recoil is a small consideration.
There are some excellent suggestions and good advice. I really am not sure I have much to add other than this.
Low recoil and power delivered down range are almost two mutually exclusive entities.
If you are interested in a gun for your son look at his size, his experience, and his ability to tolerate recoil. Consider the 243, 260 (I really like this round), the 25-06. All are great mainstream rounds with quite moderate recoil. All can deliver the energy to cleanly take deer sized game to responsible ranges. If you don't mind a little exotic the 6.5X55 is a great long range round with moderate recoil. The 7X57 is an excellent round also.
If you are more interested in power delivered down range the 270 is a great choice and IMHO with the 25-06 are great starting points for long range rounds. Other true long range rounds (MPR approaching or exceeding 400 yards) include 257 Weatherby, 270 WSM, 270 Weatherby, 7 Mags of any flavor including (especially the 7 STW), and the varying 30 caliber magnums. None of these are necessary for deer hunting but all allow a great deal of energy to be delivered down range with a flat trajectory.
If I already had a 308 I would look to a 270 next. I love it. However IMHO there really is not much difference between the 270, 280, and the 30-06. All are great rounds for almost all north American game.