How do I connect 2 computers wireless I have a wireless linksys router - not hooked up yet . Main computer is connected to comcast broadband . Help what do I do ?

Here's a coupld of How-To's for networking
Wired networking Guide (http://www.microsoft.com/windowsxp/using/networking/setup/wired.mspx)
Wireless Networking Guide (http://www.microsoft.com/athome/moredone/wirelesssetup.mspx)
Should give you some more ideas.

Not only do you need a wireless router that your modem plugs into (WAN port) but your computers need to have wireless capabilities. (Even though most wireless router have ports you can hard wire to.) but to go wireless, your computer has either built in such as in newer laptops wireless 11 b or g is already built in OR if there is no built in capabilities you need to by a USB adapter (preferred method) to receive the wireless signal. There is also a wireless PCI card that you have to remove the desktop's cover and install into the PCI slot (Usually white in color) or a laptop card that slides into the PCMCIA slot on one side of the laptop.
If you purchase at best buy or circuit city or similar store a CD comes with the equipment. Put it in and install the software. After that you can usually get to the internet from there.
If you have security enabled you have to enter a key code or passphrase. The software automatically will scan for networks within its area and you can just click on your network and click connect. Usually you only have to do this once unless you connect to other networks outside you home.
Hope this helps.
Good Luck