Here are a bunch of resources that will help you in your journey. Most of these will be based on the Windows platform.

Netstumbler : Ultimate tool for detecting Access Points, Wardriving. Very easy to use application and they also host a great forum on WiFi.

Packetyzer : Great sniffer that will let you see exactly what the network is doing behind the scenes.

NSSpyglass : NSSpyglass will alert you to NetStumbler's and WarDrivers in the area looking for access points with NetStumbler.

Stumb Verter : Import Netstumbler logs into Microsoft MapPoint

Netstumbler Forums: Discussions on WiFi and Wardriving

Wardriving : Great articles and links to Wardriving

WiFi Maps : Detailed mapping of WiFi Access Points. You can also contribute. :)

Wiggle : Another WiFi mapping web site.

Massachusetts Network Stumbling : Tons of good info on WiFi.

Lincomatic's Wireless Corner - Looking to build a DIY antenna?

FAB Corp - Online store selling antennas and other WiFi equipment.

Have any links that you want me to add? )( Email them to me.