In my case I just have a power supply and a motherboard with no processor connected, GPU, RAM, etc. Just the motherboard and the power supply. I plugged the 6+2 PCI-e (for the graphics card power) plug into my eight pin CPU socket. I decided to plug the PSU into the wall to see if anything would happen and the only thing that happened was the motherboard's green light turning on indicating that power was being received. I called a technician about this and he said that in order for the power to be channeled to different areas on the board, you needed a CPU installed... so I was safe. he said that if i did have a cpu installed, the pci-e plug would have shorted out my board and could have fried my motherboard, but since i didn't have a cpu installed i was perfectly fine. i assumed this to be true, as well, as the CPU is essentially the brain. hell, the power supply's fans weren't even spinning.
so, my question is... am i fine? i like to get confirmation for my answers but i am assuming that i am 100% correct in my way of thinking. no CPU = no power being drawn in.
you're probably asking, "why did you do this?" and the answer to this is simple: "this is my first time actually getting down and building a PC". i actually know all of the proper connectors and sockets now.