Protecting yourself is neither complez nor expensive. You only have to add the following four key ingredients :
1. Redundancy :
You must, at all times, have access to multiple copies of the data. This enables you to be projected against file corruption, wheter intentional or not, that you would detect after having already done one backup. The action of a virus or a disgruntled employe would be good examples.
2. Frequency :
Backups must be done regularly and not only when judged necessary..
3. Offsite :
Your backups must be offsite. They will not save you if they are destroyed in the fire or stolen along with the rest of the equipment..
4. Automated :
For most people, running backups is a too-often neglected chore. Manual operations like rotating backup sets and offsite transport is far down the list of priority. The less manipulations are required the more rigorous and reliable the backup process will be. In other words, by automating we prune all omissions, intentional or not.