Easiest way... unplug the wire, turn on the wireless, and see what happens. Something should pop up that will direct you along the way.
Alternative approach: go into Control Panel, Networks, and start sniffing around the "Add a new network" icon critter. That should walk you through the process.
I have both a wired and wireless network set up on both my laptops. Interestingly, you can use both at the same time...
