A totally simple, easy to use, VERY user-friend appp, and "man's best friend," check out
Fetch!.
IT behaves much like OS X, in the sense that it's drag and drop. OR you can use the "get" and "put" buttons when you're in the desired directory.
Does have encryption support, and most basic FTP functions that you'd want.
AND!
It's free. So enjoy!
Also, the server that you're trying to log into, check with the admin, or if it's yours, make sure the directories have the proper disk permissions so that it can be written to from a remote connection.
PS. I use this app to FTP from my gf and I's G4 Powerbook into my soft-modded original Xbox to put media on it (as I use it as an HTPC/media center). IT works gracefully and does everything I want it to.
It's so simple, I even got her hooked on using it.
