Nice present to your boy! OpenOffice is for windoze too, so you dont have to setup linux for him ... if he wants it in some years, he will surely do it himself
Sports ? What is that ? hehe, show hime some creative computer programs: grafix, sound and maybe flash and other cool/fun tools for him to enjoy ...
And let him enjoy the good time games bring you, its fun no mather what age you are IMO
