There are a few popular places to get a FTP program. Below are a few of the sites that Bluehost.com recommends:

An FTP client for Windows is available at
http://www.ipswitch.com or http://filezilla.sourceforge.net

As General Software download site
http://download.com (Recommend Core FTP Lite)

An FTP client for Macintosh is available at
http://www.stairways.com/anarchie/