Let me address just two issues worth considering: guest access in FTP and the particulars of turning on and using SFTP.
With Leopard, FTP access is controlled identically to AFP and Samba. The one exception is that—at this writing—guest access does not work with the Guest account.
To work around that, create a special Sharing Only account called
guest_ftp (or whatever you choose), give it a password like
guest, and assign it to any shared items you want
to enable guest FTP access to. Then, to provide a link to the file repository, tell your
users about the account or even publish the account name and password on any Web page you
need to provide a link to for the file repository.
In a future edition of this ...