Online IBM manuals (V5R2):

• Programming Languages
  • Iseries Information Center
  • API’s
  • CL
  • DDS
  • Socket programming
  • XML
  • QSHELL
  
  
• System Programming Support
  • FTP
  • IFS
  • OS/400 PASE
  • Windows server
  • EMAIL
  • Iseries Net Server
  • IBM API Lookup
  • IBM's Alpha Works
  • IBM's CGI Information site
  
  
• System Operation & Management
  • Backup & Recovery
  • Basic Operations
  • Journal Managment
  • System Values