Well, you can see the connect the little whie connectors into the motherboard first. Theres a long one, 20 or 24 pins. Theres also a small square 4 pin, connect that too. You can see where they go on the motherboard.
Its a lot like those little childs boxes with the squaure hole, circle etc, then you gota put the right shapes in.
Oh yeah, theres a little connector you gota plug in at the back, called a kettle plug. Its the power cable, You plug that into the PSU, then plug the other end into a wall socket.