HP-UX

HP: IT Resource Center
Americas/Asia-Pacific site offering online support. Includes knowledge base, patches, drivers and security mailing lists.
http://www2.itrc.hp.com/

HP-UX System Administrator Resource Page
Has sample questions to study for the HP-UX System Administration Certification.
http://www.networkessentials.com/certified/hpux

Tek-Tips: HP-UX Forum
Technical support forums and mutual help system for computer professionals. Selling and recruiting forbidden.
http://www.tek-tips.com/threadminder.cfm?pid=51