The Steinberg Knowledge Base
http://www.steinberg.net/en/support.html
Steinberg's Cubase site
www.cubase.net
Steinberg's FTP for downloading updates
ftp.steinberg.net
ProRec has lots of information and advice on recording - digital and otherwise. Check out the Archives section.
www.prorec.com
Auxbuss Publications - Cubase SX Complete.
www.auxbuss.com/index.php