I know that on a standard case, one would plug the case HDD light straight to the motherboard. Okay,

So If you have 2 or more hard drives, and you want to know which one is being "accessed" where does one wire led's to?

This is going to be more of an art thing than it is actually useful. For my custom case, it will have a standard on light and a hdd light, but you can flip a switch and I will place LED's along with the wiring, So that when hard drive one is being accessed, you can see the red lights follow the wire to the motherboard. Power will just be green LED's and a green LED heatsink on the processor.

There are free downloadable software add-ons that will report EIDE, SATA, and USB installed devices. They work fine. Not many people use them, as hardly anybody needs to know... I find mine very useful for when I have a camera and other USB devices plugged in.
For hard drives, you have computer management in Start->Control Panel->Administrative Tools->Computer Management->Storage->Disk Management that is plenty good enough for me. .

huh?

I'm not talking about putting the stuff on the screen. I'm getting a mega load of red and green led's to put in the case (which the front is clear) so when you decide to see pretty colors, you flip a switch and the lights to each hdd light up as it is accessed. I want to know where can I tap into inside the computer itself to get a HDD light for both drives. Like I said, its very useless, and is only for show (since it hangs on the wall)