My iPhoto Library is on an external hard drive. I want to copy it to another hard drive as a back up. It looks like Time Machine only backups the internal hard drive and selected externals. I don't want to back up my internal. I only want to backup my external. What do i do? What programs will do this? If Time Machine does do this, please explain how. I don't see that option.
Copying files/folders/bundles etc. from one location to another is basic Finder 101. Have a look at Mac Basics: The Finder organizes all of your files to gain a more complete understanding of the Finder app. While the KB doesn't explicitly mention "Copy" nonetheless you'll see it on the picture of the Toolbar Action menu.
Drag and Drop works too as well as standard Keyboard shortcuts like ⌘C for Copy and ⌘V for Paste, which are on the Edit menu.
So in Finder, select your target files/folders/bundles etc. and preform the requisite actions in one form or combination thereof.
Using the iPhoto Library bundle as an example, you'd select it in Finder and then press ⌘C and then navigate to the location you want the copy and then press ⌘V. This action will then copy the iPhoto Library bundle from its source location to is destination location.
If you do not what to do this manually all the time you could script it in many different ways or simple use Time Machine to keep it backed up.
Since you do not want the internal drive (Macintosh HD) backed up, go to System Preferences > Time Machine > Options and add the Macintosh HD to the Exclude these items from backup list while making sure the source external drive containing the iPhoto Library bundle is not in the list. Note that the drive must be mounted to see it in the list.
Save the changes and now back at the main Time Machine panel click the Select Disk... button and select the other external drive you want to use for the Time Machine backups. Note that both the source and destinations disks must be formatted with the native OS X filesystem for this to work.
Then if the Time Machine OFF/ON switch is the to OFF set it to ON.