I did attempt at a PSP Go tut for the LED mod but, it took forever to post and my computer froze part way through so i gave up. But like i said i can provide high res pics of the psp go mobo and stuff for the tut.
Also there are several place from which to draw power from the psp mobo, it just depends on what you want the power for. My personal favorite spot is from the bluetooth adapter or the wifi adapter.
Both of which are hard to get at but can provide sufficent power to run led's and will turn off with the WiFi/Bluetooth power switch on the side. So if you are making a tut that might be a good place to start.
I would recommend the actual switch itself if there wasn't lots of heat sensitive parts right next to it. (i mean the resistors next to it).