Like BlackKnight said, Netstumbler is the best I have found for windows. However, I do quite a bit of wardriving myself, and I vastly prefer to use Kismet. Kismet is for *nix though, so unless you are into that you can't use it. As for cracking WEP, Airsnort is your best bet. There is a tool for win by Wildpackets called AiroPeek that is supposed to do that as well, but I have yet to try it myself.
All of these tools can be found
here with the exception of Airopeek, which the demo can be found
here Infinite