About 2n2222 LED mod.

[zephyr1220]

I am now trying to do the 2n2222 LED mod, But i want to know the voltage thats coming inside my LEDs.
I saw in tutorials that the positive side is connected to the 3.6v or 5v source.
The only connection that i know is the 5v connection according to the lm386 tutorial.
Is there any 3.6v connection in the mobo?
And does that mean when i am connected to the 5v, 5v is the voltage going in my LEDS.
HELP PLS>