Here are some general Unix reference sites you might find useful:

• Web Monkey. This site has some great tutorials about all kinds of Internet topics such as html, CGI programming, etc. They also have a nice quick reference sheet to help non-Unix users navigate around.
• Geek Girl. Don't let the name fool you, this site has plenty of information regardless of gender. It too has a good general Unix command summary, which is a mirror of information produced by the University of Edinburgh UK.

For some more advanced information, some good sites are:

• Unix Guru Universe. This site is a portal site with links branching off everywhere.
• Stokely Consulting. Celeste Stokely provides a well known tutorial for managing printers and serial devices under Solaris. Celeste has a good page discussing what she considers the golden rules of consulting.
• Randy Marchany of Virginia Tech has a good Solaris 2.6 Administration tutorial online.