VT,
Well done. The important thing now is to configure the backup program to do regular, incremental backups. Because only new or changed files will be backed up, it takes very little time. I set mine to run at 1am each day.
If you do this and you have a drive failure sometime in the future, in the worst case, your backup will only be one day out of date. Don't forget to copy some files from the backup, once in a while, just to make sure your backup drive is still working correctly.