Hmm, ok, to understand what you're doing and why you're doing it you need to know how a humbucker works compared to a single coil I think.
OK, a single coil is a magnet (or 6, one for each string) surrounded by a copper coil, as the string vibrates the pickup creates a small electrical signal, this is then fed to the amp.
A humbucker takes two single coils, on one of them the magnets have the opposite polarity, north becomes south and vice versa, and the coil is wound in the opposite direction. What this does is it inverts to polarity of the background noise without reversing the polarity of the guitar, effectively "bucking the hum".
So, on a single coil you'll have two wires, in and out, or hot and ground or whatever you want to call them, basically one from each end of the copper coil (there may be a 3rd which will always be ground). On a humbucker there will be four, two for each coil (or 5, again, always ground).
To get the big beffy fat sound of a humbucker they are wired in series, this means that the sound comming from one gets fed strait into the other so the sounds are added together.
Some humbuckers come with the coils already wired in series internally so you will only see two wires, others, like yours have all 4 exposed. This is to give you the option of having only one coil, or wiring them in parallel which will cut out the hiss but the sounds will be averaged instead of added so the output won't be as high and the tone will be brighter.
So, to wire the pickup as a normal series humbucker; the hot for the first coil would be your hot, the ground for that coil would go strait to the hot of the next one, and the ground for the second coil will be your ground for the pickup.
Sorry if that's long winded, but I hope you understand now why you have 4 wires instead of two.
