Throughout my blogging years and web experiences Filezilla has been of great use. The Filezilla client allows transfering of files through FTP, FTPS, and SFTP. Actually, you can also delete files on your server or rename them.
It runs nicely on Windows, Linux, BSD, Mac OS X, and you can run it through a USB drive with Portable Apps.
If you prefer to run something similar on your Firefox, you may also try out FireFTP.
By the way, get an FTP client from time to time and download all of the server files to make sure you have a safely secured backup. 🙂