If you are hosted at DreamHost, your "ftp home directory" (where you end up when you connect to your server at skitty.us) is usually /home/yourusername.
Inside that directory should be a directory for skitty.us, and your "private" directory should be visible in that directory. To "get into it, you first "change directory" in your ftp client to your skitty.us directory.
Once you have done that you should see the "private" directory, and you can "change directory" into that directory just like you did to get into your skitty.us directory.
In fact, when I browse to skitty.us, I can see "private" as a directory (but it is not password protected, at present).
The exact manner in which you "change directories" differs depending upon which FTP client program you are using - for most "graphical" clients, you just click (or doubleclick) the destination directory's name.