My laptop connect to the internet with my linksy router that is connected to my PC in the living room. Now my son has a computer. Can he connect to the internet from that same router?

Yes, using the same method you used to connect the laptop. As long as he has a wireless card/usb stick in his computer or and ethernet cable from router to computer. Let me know if you have problems, I'll be happy to help!

Regards

GadgetBlogger