To format a 3.5-inch, high density floppy:
$ fdformat /dev/fd0H1440
$ mkfs -t ext2 -m 0 /dev/fd0H1440 1440
For a 5.25 inch floppy, use fd0h1200 and 1200 as appropriate. For the B: drive use fd1 instead of fd0.
The -m 0 option tells mkfs.ext2 not to reserve any space on the disk for the superuser—usually the last 10% is reserved for root.
The first command performs a low-level format. The second creates an empty file system. You can mount the floppy like a hard disk partition and simply cp and mv files, etc.
Device naming conventions generally are the same as for other unices. They can be found in Matt Welsh's Installation and Getting Started guide. Refer to ("Where Is the Documentation?") A more detailed and technical description is Linux Allocated Devices by H. Peter Anvin, firstname.lastname@example.org, which is included in LaTeX and ASCII form in the kernel
source distribution (probably in /usr/src/kernel/Documentation/), as devices.tex and devices.txt.