Some basic commands that might be used were listed by SaranAS400. Rather than getting too tied to commands, I suggest that you use iSeries Navigator (or whichever Navigator is appropriate for your system) for almost all of your monitoring and control.
You should definitely become familiar with commands and the command interface, but you’ll be much better served in your day to day work if you learn how to use Navigator for the vast majority of your tasks.
As for which jobs to monitor, there’s no way we can answer that because we have no idea what you run on your system.
To check all printers WRKWTR
To check jobs on a printer WRKOUTQ PRT#
To display your message screen DSPMSG
To display System Operator messages DSPMSG QSYSOPR
To look at your spool file SP or WRKSPLF
To look at a person’s spool file WRKSPLF and their username
To see someone’s messages DSPMSG and their username
To work with active jobs WA or WRKACTJOB
To save something on a spool file Put a 2 by the file and type SAVE(*YES)
To change a job to different job queue Put a 2 by the job and type JOBQ(QTXTSRCH)
To look at QBATCH job queue WRKJOBQ QBATCH
To look at QTXTSRCH job queue WRKJOBQ QTXTSRCH
To work with scheduled job entries WRKJOBSCDE
To assign a sp file to another printer Put a 2 by the file and type OUTQ(printer name)
To check if printer is varied on/off WRKCFGSTS *DEV PRT15
To check Warehouse orders / queue WRKOUTQ W*** (***** = warehouse #)