I agree. Just a couple of additional points:
If you study your CD-writing software, you should find out how to write
"track-at-a-time" without finalizing the disk. That will let you continue
writing other files to the same disk later, so you don't have to waste a
whole CD for one file and you don't have to wait until you're ready to write
a lot of files at once.
As an medium for quick but temporary backup, a 64MB or 128MB USB key (aka
"thumb drive") works well. You just plug it in, write to it (it's almost as
fast as a hard drive), and unplug it.
Floppies are pretty much worthless any more: too small, and too prone to go
bad.
In any case, NEVER open a Word document directly from any removable media or
save from Word directly to removable media. It's an invitation to corrupted
documents. Always work only on the hard drive, and copy to/from other media.