on the motherboard bottom edge where the sata ports are. the first set of pins on the left is the mb case header cables. in the mb guild read the pin outs and plug your case wires into the header pins.
on the motherboard make sure with the power off that the eight pin power on the edge of the mb is plugged in and on the gpu both power plugs are connected. if you plugged the pins and plugs in right and put the mb n top of the standoffs the mb should post and the video card should stay green and there should be a mb bios post screen from the video card.