The backup job won't appear in the job monitor until such time as it has completed running (bottom half), or is either currently running or scheduled to run (top half).
Have a look within Job Setup, your backup job should be listed in the top section titled Jobs. If you don't see it listed there, does it show up in the selections list. Make sure in the Device Name column that it is set to use your drive.
One thing to note if you can't see your job listed is that where you enter a name for the job under selections is not the actual job name, that's entered within Settings, General section.
Once you've found it, go to the Schedule section, and tell it when you want to run the backup. Once you click OK you'll probably get a message up confirming the job has been scheduled, after which it should appear within the Job Monitor.