Several years of Un*x systems administration experience, primarily with Linux.  Some experience with Digital Unix (OSF/1), SunOS, and Solaris
Excellent understanding of the Internet and Internet systems
Very good knowledge of DOS/Windows systems/hardware
Currently pursuing Microsoft Certified Systems Engineer status, with 4 out of 6 exams completed (those completed include MS WinNT 3.51 Workstation, MS WinNT 3.51 Server, MS WinNT 4.0 Server, Networking Essentials, and MS Internet Information Server and Index Server).  
General Macintosh knowledge