There is no magic "antenna" that you merely hook to your PC, and then relay around your house.
This site tends to be more for the hardcore guys, not beginners. If also tends to focus on Netstumbler rather then WiFi in gerneral, although there's a lot of good general knowledge here. If you just dive in at this site not knowing any of this stuff, all that will happen is frustration on both sides. Yours for not knowing what the hell we're talking about and ours from trying to teach you to run before you can crawl.
There's so many options for different ways to accomplish what you want to do, that you need to define that first. To define it, you have to ave at least some idea of what the equipment is, how it works, and what it is called.
You need to learn about the equiment and technology first. I'd suggest looking at some consumer level sites like
Linksys. They have basic explainations and diagrams. Once you have a more concrete idea, you shouldthen look around at some
basic networking sites. Try
Practically Networked for a start. Search on "networking 101" on this site for more detail. (You need to also know how a computer network functions, as this stuff is networking with radio.) Now go to the nearest Staples, Circuit City, etc. to look at the equipment and ask questions. (Don't by yet.)
Then purchase "Jeff Duntemann's Drive-By Wi-Fi Guide." (The author hangs around here, too. Screenname
Novilio) Jeff's book will pull it all together for you. Look at this thread for details:
http://forums.netstumbler.com/showth...&threadid=6901
Finally, come back here, and ask questions before you buy. You should be able to speak "WiFi geek" by then, and be able to ask the correct questions, and we can give you good answers.