Manual pages can give you lots of information and references to other commands. Try:-
man vmstat
man ps
man iostat
man netstat
etc.
There are often real-time monitors included, such as nmon or top and there may be others that can be suggested. Are you particularly worried about something? Do you have any symptoms?
Thanks,
I am currently working with Solaris 8 and 9. I just need to see if the system hardware is in good working condition, network connectivity, Ram issuies... just don't know what to look for because I don't have have GUI hardware diagnostic tool that generates all the fancy graphics regrading the system information and such.
This is the analysis tool oracle support expects you to have when there is a problem (and you create a help ticket with them). It is usually already installed on old systems because sooner or later you have to call support. Works on all platforms.