need input please

ok heres the deal, we have a imac downstairs as a family computer we use verizon dsl to get online, my son just got a gateway for his room upstairs. he wants to use a wireless router so he can have internet access, but im a little hesitant about going that way only because of the hacking i hear about? am i being paranoid? i was thinking, why cant i run a ethernet cable out of my dsl modem and hook it up to his pc? or is there another way of doing this? input is really needed here....thanks, and sorry about a long post.

You will need to add a router in either case, wired or wireless.
A member here, cwa107, created a nice FAQ thread for wireless networking. There is a nice section on wireless security. Link

I hope this helps.