The problem is likely caused because you were logged in as root when you created the folder, so the folder and its contents are owned by user root of group root, and the permissions need to be changed to allow non-root folks to see it.
First a forewarning - NEVER allow root access to ftp!! Vsftp is my preferred FTP server, and it wisely doesn't allow root to log in, unless you change its base configs. The problem with allowing root to log in is that anything can be done to your system with root access. Huge security risk, and completely unnescessary.
To allow people other than root to see and access that file, you'll need to use the chmod and chown commands. Before you do anything, give the commands "man chown" and "man chmod" (without the quotes) to your terminal. You should read the pages describing these commands.
I will speculate that you have another user set up on the system, who I'll call user. Since you created the folder as root, you need to be root to change the mods on the file, so sudo or su yourself prior to trying these commands, or they won't work.
#chown -R user:group /path/to/directory_created_by_root
#chmod 644 /path/to/directory..........
That should clear up your problem. You may have to tweak the individual files as well.
The 644 gives the owner the ablity to read and write the file in question, and the 4 gives everyone else the ability to read the file, but not to write to it. You can use chmod on the directory where the ftp server runs, and the 4 (read only) mod will allow your friends to log on and see the files, but they can't write, so it won't allow them to change it in any way.