Your son has a new laptop and you want to get him on-line - yes?
You already have a PC that connects to the Internet - yes?
You would wish now and again to have both machines using the internet at the same time - yes?
You need a router (wireless broadband is best) plugged into your 'phone line and you can have both machines and the house telephone all working down your telephone cable.
Each computer needs a wireless device (built in or an internal card or external USB wireless card). Each machine needs a device driver to operate its own wireless device.
You need a broadband service contract with the ISP of your choice. In the UK I use BT Broadband and all of our seven computers can connect simultaneously.
See here...
http://www.broadband-finder.co.uk/broadband-directory/bt-broadband/#provider
I installed their Option 1 for my mother in law last week - took less than an hour to get her on line - took 3 days to arrive after placing order.
I don't think the "piece of wire between the two machines" is a realistic solution for you...
If you already have a wireless router you should be able to plug an ethernet cable from his laptop to the router to get the boy on line - direct connection to router rather than wireless connection.
Good Luck...
Peccavi, December 2008