FTP stands for file transfer protocol (among other things) which is a common method to transfer files over a network.
you need a few things:
an ftp client - many operating systems have in the least a command line client. there are many free graphical clients such as Filezilla. If you don't have a client already, download one and install it.
a host - in this case, ftp://h-a-z.org
a username - diyhfxpublic
and a password - d1Y4fX66
once the ftp client is connected, you can transfer files and directories into the uploads directory on the server. If the files are suitable, they will be moved to an appropriate directory on the server.
if you need help, or if you would rather just email files, send them to admin(at)h-a-z(dot)org