Routine for a young boy 15

[Sperwer]

He's old enough to start training. Starting Strength by Rippetoe would be a great place to start.

I second this. It's the first and best book I've run across with a compelling account of the mechanics for anyone who wants or needs to have an explanation that they can sort through themselves as a supplement/alternative to hearing it from a "trainer", who these days may or may not know what they are talking about. I recently gave my original copy to a very good friend's 15 year old daughter, who has decided she is a boy, and she is eating it up along with the weights.