Assuming both computers are using the same version of Word:
To save to Floppy:
Create your document,
click File>Save As...
Where it says Save in, click the drop down arrow and choose your floppy (a

drive (make sure there's a disk in it!).
For File Name, enter the name of the file. Click Save.
To open on second computer:
Now take the floppy to the other computer,
Open Word,
Click File>Open...
Where is says Look in, click the drop down arrow and choose the floppy (a

drive.
Either double-click the file or highlight it and click Open.
(You could also put the disk in the second computer, double-click My Computer, double-click Floppy (a

, and then double-click the file.)
To save on hard drive of second computer:
After you've opened the file on the second computer, click File>Save as... and choose where you would like to save it.