Its posted bit by bit in almost every power thread. Also, it is kind of my thought that there aren't too many people with power issues, at least not after the initial steps!
I use a M2-ATX and a M10k, and a 3.5" HD. I ran 4gauge (I think, it's thicker than my thumb with insulator) power from hood and then ran 8awg (I think, it's about just over half the width of the power cable) for about 3 inches to a bolt. I get some high pitched alternator whine with the AC on, but that is due to my lack of a powerful enough alternator. I'll probably kill it quickly at this rate. My PC turns on when the car starts, and usually when I see my car, I push the remote start, and when I get there windows is loaded and playing music.