You can slave another ide drive to the cd/dvd drive on the secondary cable. But that can slow down your performance at times when trying to access files there and load files from it or the other drive slaved to primary host drive. No ide drive will connect to a floppy cable. If your board has SATA capabilty with an onboard controller you can add more drives there for storing addtional files. You can also go with larger ide drives.
Many are now using external usb drives to store larger amounts of files and data. Those simply plug into a usb port. With a dvd burner you can also create data dvds for additional storage if you have the right software. One free cd/dvd burning software is called BurnOn found at
http://www.burnworld.com/burnoncddvd/