Backup Data Storage

I have two questions. 1. How are other authors maintaining backup storage of their data? Presently I am copying to a CD-R disk on a bi-weekly basis. I store this disk off site from my home (just in case of damage to my home or computer). 2. When you are proofing your manuscript, and have several drafts printed, how many drafts are you keeping? Do you need these drafts with handwritten corrections to verify that you are the original author? Thanks a bunch for your responses. Carolyn Orr