how do i connect my PC COMPUTER to a wireless network?

Does the PC have built in wireless? If not you will need either a PCI wireless card or a wireless USB dongle.

Have a look at some of these routers and buy one (or two to set up a wireless network).
http://www.buffalotech.com/products/wireless/routers-and-access-points/airstation-wireless-g-high-power-router-access-point-whr-hp-g54/

it is going to depend on the router or wireless access point. It is best, and many routers require, that initial setup is done over a cable. And they generally come with a cable. Just follow the instructions.

Of course, as noted previously, your computer will need some form of wireless hardware itself.