Help with stereo and turntable cables please?

Right, I recently bought a new turntable, the "Numark TTUSB". I also have "Teac TDX250i" stereo. I want to connect the turntable to the stereo speaker system (Both the side speakers and the sub woofer). There is a red and white RCA output from the turntable and a red and white input for the sub woofer. When using the stereo normally there is a red and white RCA cable connecting the sub woofer and the two side speakers. I think the side speakers have to be connected to the sub woofer for the system to work? I know there are various RCA splitters and extension cables but I really don't have a clue what to do! Any help would be very helpful... Thanks in advance!