Complete Wardriving Guide
This is the White paper on wardriving (in .pdf format). It covers equipment and software needed. Also contains information on how to detect when you are the target. Another helpful link is the Wardrive FAQ. Put them together and you have a pretty complete guide.
Note that this guide is over 3 years old… It’s really not practical to have a dedicated computer (off your WLAN) constantly listening for *potential* wardrivers. Anyway, some information can’t hurt if it’s meant to be for your own safety.