Here are a couple intersting articles on wireless networking over on the O'Reilly Network.
First up is "When Is 54 Not Equal to 54?", which provides an examination of the 802.11 a, b, and g protocols, and explains why you may not be getting the advertised speed.
Second is " Dispelling the Myth of Wireless Security", which, obviously, deals with wireless security, and offers tips to test the strength of your network's security and encryption.