iStat Pro , how do I use it correctly

[star555]

with the kind help of forum members ive now got iStat Pro up and running on my new iMac, and its just struck me as
a Mac newbie , what do I now keep an eye on when looking at my new iStat Pro display , showing all this wonderful information . Some of the information is self explanatory
but I could do with further help from forum members to
advise me just what to watch and keep an eye on with all this new information, I am not too really sure about , how can I tell if some thing in the display information may not look right IE too high a temp or too slow a fan sped ..? , its wonderful now having all this exter information , but what do I now do with it ..

could some one please point me in the right direction with the following items..

TEMP ( how do I know if the reading is OK )


CPU A

CPU A

GPU ( what is this ..? )

GPU DIODE ( what is this ..? )


GPU HEATSINK ( what is this ..? )


AMBIENT

MEM CONTROLLER ( what is this ..? )


AIRPORT CARD

HD BAY 1 ( what is this ..? )


OPTICAL DRIVE

POWER SUPPLY 1

HD : MACINTOSH ( why 2 , ) ( HD BAY 1 above )

FANS ( How do I know if the speed is correct )

CPU FAN

HARD DRIVE

OPTICAL DRIVE

please bear with this Mac newbie still on a learning quest