Normally the floppy is on its own connector and doesn't use the 'normal' IDE channel that hard drives and CD/DVDs use and has a different connector cable. It sounds as though you need another Hard Drive connector cable which will fit into a slot somewhere near the one that your hard drive is connected to.
You would connect your CD and CD writer to this second channel. You need to set the jumpers on the back of 1 CD to be a master and the other as a slave. Hopefully a diagram for the correct setting will be printed on a sticker on the drives or in the instructions. A jumper is a small piece of plastic that connects 2 of the smallest pins on the back of the unit together.