Don't know how RH organises their desktop, but down at the command line level everything should be pretty much the same. The Linux Cookbook has quite a useful section on using floppies:
P.S. you enter commands at the prompt (usually a % or $) in a terminal window (also called a console, shell or xterm). I would think any desktop has a menu entry for starting such a thing.
For mounting/unmounting disks you typically have to be the superuser. Type 'su' at the prompt and give the root password. The prompt should change to a '#', indicating you now have superuser powers
One more thing -- if you have the 'mtools' package installed you may be able to access the floppy directly (assuming it is MSDOS format). This gives you equivalents of MSDOS commands: e.g. mdir, mdel, mcopy etc.