%COMPUTERNAME% PC Name
%HOMEDRIVE% User's local drive letter
%HOMEPATH% Path to user's home directory
%HOMESHARE% Share used to house user's home area
%LOGONSERVER% Machine that authenicates user logon
%OS% Operating System (ie Windows_NT)
%PROCESSOR% CPU
%USERDOMAIN% Domain containing user's account
%USERNAME% Domain containing user's account

Tim Hill's text on command line scripting is outstanding. If you have an extensive background, writing bat files, forget it. Otherwise, get it.