Hi llbgeezer. The basic front panel functions are generally simple to decipher, they are 2 switches (power and reset), 2 LEDs (power and hdd) and speaker. With front panel USB, there is added to this 2 sets of 5V, 0V, data+ amd data-. then some cases also have firewire and audio sockets. Yours also has a led display, so what the connectors for that could be one can only guess.
irtx is Infrared transmitter, irrx is Infrared receiver.
I would guess that hda is hard disk activity. hdrblnkyel could be hard drive blinking yellow.
data1 (2 off), data 2 (2 off), shield and vcc sounds like the USB functions I referred to above.
The fans need to be connected to the power and ground pins. the worst that can go wrong with these is that they may go backwards. They can even be run from a 12V drive power connector. The cpu is the only exception because it may have a speed monitoring pin.