You will definitely want HDMI from Bluray to receiver and receiver to TV, 2 so far.
But you will also have to make a decision on your TV viewing. Do you want to involve the receiver when watching tv all the time like when watching the news or a gameshow or just for the cool HD shows where you want the good sound/video?
If you want to use the receiver at all times then you only need one more HDMI cable from STB to receiver.
But if you are like me I don't need 120Watt surround sound to watch the news, etc so I use component video and S/PDIF from STB to TV, and an HDMI to receiver so for normal everyday viewing I put the TV to Input 2 where the component/fiber optic is and for big sports and HD content I turn on the receiver and...