Why are you using an SPDT relay? If you bought it because you wanted a similar setup to mine, then you bought the wrong thing, sorry. You need a USB-controlled relay. It plugs into the usb port and can be controlled from windows. It's basically a flip switch, only instead of manually flipping it, you press a button (or just perform a command) on your computer screen.
Everything else looks OK. I'll help you with wiring once you figure out the relay stuff.
EDIT: the relay looks something like this: