ok im planning on doing some simple mods to my pc and i want to add leds but i want to know a few things first like how do i connect the leds to my pc (assuming i want them to be on wen i power up the pc and go off wen the pc does, nothing like switches for them or anything) and what is the smallest diameter i can get them in well basically can i get them in a 3mm diameter and do you know of any site were i can buy these from (im English so i need a site that deals to uk) and do they produce heat or use much power(im planning on installing 8 by the way so answer that last question with that in mind)?
i know a ot of these will most likely be obvious but i dont know and wan to know first before i start doing stuff 2 my pc and have it all go wrong