All of the network tools are under the Auditor menu. The full list of network tools can be found here. There are several dozen programs for footprinting, scanning and analyzing networks. Think of footprinting as network recon, where you just want to find out what is out there, but you don't want to break in yet. You have your basic port scanners such as NMap. SMB scanners are also included that will scope out available Windows and Samba shares.
Scanning involves sniffing the network. The best open source scanner Ethereal is included. With Ethereal, you get to see the raw network traffic flowing over the cable or through the air. EtherApe, which monitors how the computers are communicating to each other, is also included.
Several analyzers are included which will literally rip passwords and URLs from the network stream. For example, Dsniff will parse out mail, FTP, telnet, AIM and many other types of passwords.